Video Game / TS!Underswap

WARNING: Unmarked Undertale spoilers below and on related TS!Underswap pages.

Hello. Before you start your adventure, let me tell you a tale from long ago.

Howdy! My name is ASGORE DREEMURR.
I come through here every day to tend to the flowers.
However, today seems as if it will be an exception.
Rise, child. I shall guide you through these ancient halls.

— Asgore to Chara

TS!Underswap, or Team Switched!Underswap, is a fangame of Undertale that is currently under development by Team Switched. It's based on their own version of the extremely popular Role Swap AU known as Underswap.

The most important swapped roles will include:

• Frisk and Chara
• Flowey and Temmie
• Toriel and Asgore
• Dummy and Mad Dummy
• Napstablook and Mettaton
• Sans and Papyrus
• Undyne and Alphys
• Monster Kid and Asriel

One major difference from vanilla Underswap is that TS!Underswap aims to swap the characters but not their personalities, along the same lines as fellow Undertale role swap fan projects Storyshift and Inverted Fate. Meant to be "a brand new experience for fans of UNDERTALE," TS!Underswap also tries to switch things up by using expanded and reimagined areas and introducing new characters and original plot elements. Something else to note is that there are four routes instead of three;

• Neutral route
• Compassion route
• Ruthless route
• Aborted Ruthless / "Evacuation Neutral" route

The game started development in Game Maker: Studio in 2016, and swapped to Game Maker: Studio 2 in 2019. The first official demo was released on December 23, 2020 on Windows, Mac^note Though as of the December 2023 devlog, Team Switched has suspended plans to support TS!Underswap for Apple platforms, Linux, and Android for free. In December 2023, Team Switched made a surprise announcement for the release of Demo v2.0 scheduled for January 2024, an update making Starlight Isles^note the second main area and counterpart to Snowdin playable. This update was released on January 20, 2024 on Windows, Linux, and Android for free.

You can download the demos and follow the game's progress on Gamejolt here.

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TS!Underswap contains examples of:

• Adaptational Badass:
  • Asgore puts up a much better fight in Ruthless than either Toriel or Asgore did against the player character in Undertale's Genocide, despite both player characters being about the same LV. Especially impressive since he is physically older than his counterparts from passing his life-energy onto Asriel.
  • In Undertale, Muffet could be killed in one hit. In this game's Ruthless route, she takes several turns to kill, and also prevents you from using the FIGHT button at certain points, requiring you to make it available first. She also has more complex attacks in either route.
• Adaptational Heroism: Asgore makes a genuine effort to kill Chara and stop them from killing his people in Ruthless, whereas both Toriel and Asgore in Undertale's Genocide were mowed down in one hit without realizing how dangerous the player character was until it was too late.
• Adaptation Expansion: The first area has more areas to explore compared to Undertale, including new puzzles and an entire new city. You can talk to way more monsters in the Ruined Home overworld, there as more minibosses for the area, and new features (like the journal you can keep notes about monsters in, and sidequests to earn extra gold) to dig into.
• Adaptational Jerkass: Muffet's a lot more prone to insulting you when you talk to her after her battle, at least at first. She gets better after a cooking session where she can vent out her frustration over what happened to her.
• Adaptation Name Change: In the Demo, Mettaton is changed to Mettacrit (and later to Mettalot), while Burgerpants is changed to Bugerpant.
• Adaptational Nice Guy: Bugerpant. He's still quite cynical and he still resents his job as a Burger Fool, but he's a bit more optimistic than his Undertale counterpart and acts much calmer and more polite at his job. It's probably because he met Flara, who honestly cares about helping him with his problems.
• Adorably Precocious Child: Chara. They have a dry and sometimes sassy running commentary, take notes in their journal on the monsters they encounter along with illustrating the monsters with crayon drawings, and their sprite has open eyes but a neutral expression like Frisk's, giving them an earnest, serious look at all times, even when sitting on a bench and childishly swinging their legs back and forth. It gets extra adorable if you equip the Cowboy Hat that Chara is under the impression makes them "look tough", since they wear it in the overworld too and make a point of carefully taking it off for naps and putting it back on when it gets knocked off their head.
• Age Lift:
  • Downplayed with Asgore and Toriel: while still the same age as their Undertale counterparts, Asriel being alive has caused them to age physically, shown with Asgore now wearing a pair of glasses for his worsening eyesight.
  • As Asriel didn't suffer the fate his canon self did as a child, he grew up, and is a young adult by the time Chara arrives in the Underground.
• All Webbed Up: In the Compassion and Neutral routes, Muffet captures Chara, Crossbones, and Papyrus, having the former stuck in a large web where they can't reach their armor item at first, and the latter two tied up and dangling upside-down. In the Ruthless and Evacuation routes, she instead has Lesser Dog and Greater Dog tied up, and you fight her in the forest instead of her shop, where the FIGHT button is made inaccessible from her trapping Chara in webs during the battle, requring you to use the "struggle" act to free it.
• Ambiguously Evil: Downplayed with Flowey in the demo because his motives in the game have yet to be revealed. It's made pretty clear he's still not a sweet and innocent flower even in this world, between him hinting that Chara will need to kill to survive, Temmie thinking he's put Chara up to their actions in Ruthless and admitting to envying him as a rival in that ending, and in Neutral him not perturbed in the slightest if Chara betrayal-kills Asgore, still saying that Chara is like him and admitting to being no better than the Temmies sometimes. Still, he chases the Temmies off before they can gang up on Chara when he didn't need to, makes no move to attack Chara and take their SOUL himself, and instead is set up as an ally to them and an enemy to the Temmies for the full game. Since his ultimate goals are unknown, it's not clear if Flowey is biding his time playing a longer con on Chara than his Undertale counterpart pulled on Frisk, or if he will be a sort of... morally flexible ally leaving the active villainy up to the Temmies.
• Ambiguous Situation: Whether it is the player or Frisk compelling Chara to leave Ruined Home. Since Chara and Frisk are swapped, it would make sense for Frisk to have more of a presence in Neutral and Compassion like how Chara has more of a presence in Genocide, but statements from Team Switched indicates the player may be an In-Universe force and since we want to progress the game by leaving...
  • The Ruthless route in the Starlight Isles update teased SUCH strong callbacks to the original game, it straddles the line of outright insinuating certain characters may actually be referencing Undertale as from their past:
    • Specifically, the Boogiemen say Chara has no SOUL and Chara repeats the claim, sounding either puzzled or thoughtful; at one point in the pre-battle attacks, as Crossbones is hurting Chara through their SOUL, he asks, "i see your pain, but are you really feeling any of this?", narrows his eyes, and has a moment of Visible Silence. In Undertale, Chara was left soulless when they reawaken from the dead and then laid claim to Frisk's SOUL after Genocide, but here they should have their own SOUL still. Napping in the hotel in the area also has them ramble incoherently about a past experience that would fit if they're recalling being controlled in previous Genocide runs by players. Their reaction to Asriel's name being entered at the naming screen, and to dialing his number at random in this update, also seem to suggest they feel Wistful Amnesia for someone they shouldn't know yet. However, this could also simply be commentary (like the protagonist in Undertale) behaving like a soulless person, and Sans' comment could be attributed either to Chara becoming numbed to everything from the violence and repeated loads or Sans referring to the true culprit (the player) not actually feeling the pain he's putting Chara through, as he does turn to the camera at times as though Addressing the Player; the hotel dream may also be commentary on people playing Ruthless in the first demo, or Chara remembering something from their life on the Surface. Lastly, it's possible their connection to Asriel can be explained as coming from either Frisk (if Frisk is attached to Chara in some fashion as a ghost) or is a simple Call-Forward setting up them up to be kindred spirits and friends.
    "(...)
    Why does this feel so familiar?
    Nobody's around, but I can feel eyes on me...
    I... I'm not strong enough.
    It's not enough.
    It's... it's never enough, for them. For anyone.
    I do what I'm asked to do, but...
    They won't leave me alone.
    Leave me alone.
    Leave. Me. Alone.
    Leave me alone Leave me alone Leave me alone Leave me alone Leave me alone Leave me alone"
    • In his fight, Crossbones initially seems to recognize that he's fought Chara/the player before and drops a few VERY suspect lines that for anyone aware of the Genocide route in Undertale and his role in it, seeming to outright confirm he is actually be the Sans from Undertale who's already experienced a Genocide route and escaped to this world, as popular theories suggest he did between Undertale and Deltarune (either jumping from the Undertale Genocide route after being "killed" to escape to Deltarune, or being a refugee from Deltarune coming to Undertale pre-game after he couldn't return to his world) ... but then as it goes on, spins it as a comic book style story about him being on the run from "the multi-watchers" and hiding on different worlds from then, sinking that theory. He cheekily reveals the whole thing was from one of his comic books... but then brings up the possibility "some part" of it could be true and taunts Chara/the player with the fact they'll never know either way.
    '"i didn't think this one would be it either. y'know. something or other always makes things end this way. and it's not like i wanna expect the worst. but you don't make it easy. what's with the face? you know exactly what i'm talking about. you and me... neither of us belong to this world."
    "yet, it seems no matter which world i hide in... (raises eyebrow) i always seem to end up throwing fists with children at the end. and that's certainly a pattern. leads me to believe we've fought before. in different forms, perhaps, but with the same intent."
    (after he admitted he made it up) "wanna know the best part? maybe i wasn't lying to you. not entirely, anyways. maybe, just maybe, some part of those goofy stories were true. either way, you'll never know. and no matter what happens next... that simple fact will never leave you alone."
• Anti-Frustration Features: Just like in the original Undertale, falling through the floor enough times during the "Don't step on the leaves" puzzles will have the whole floor turn solid.
  • When you reach the end of the puzzle gauntlet, there will be a door that takes you back to the beginning of Ruined Home. Reaching the City of Old will make another door available as well. These serve as a way to visit earlier areas without having to backtrack all the way through Ruined Home (especially since the bridge to the city gets broken).
  • The game actually bothers to tell you that you can slow down Chara's soul by holding X, making particularly dense bullet patterns easier to dodge. The fight with the Ruined Knights is meant to teach you this if you don't know it already.
  • The Demo V2 introduces a setting that allows you to adjust the difficulty, affecting how much damage you'll take in battles in case you're having too much difficulty dodging attacks.
  • V2 also brings in a similar mechanic to one from Undertale Yellow, where exhausting a certain number of kills in a room while on a Genocide run triggers a "..." accompanied by a buzzing, indicating that it's time to move on.
  • During the fight against Harry and Larry in Koffin Keep, you won't have access to your items. To compensate for this, some of their bullets will be coloured green, allowing you to still be able to heal.
• Bedsheet Ghost: Mettalot, since he is still in his original ghost monster body in this game. He still manages to stand out as flashy as ever with his pink-and-yellow coloring, styled hair, and floating gloves.
• Beware the Nice Ones: Asgore will not hesitate to kill you on a Ruthless run, and if you spare him and then try to enter his house, he'll angrily yell at you to Get Out!
• Big Bad Duumvirate: One of the reveals from the demo. You thought just one sadistic, manipulative megalomaniac after your SOUL was bad? You remember how there's a whole village of Temmies in Undertale? Yeah, now you've got SEVEN evil little fuckers after you. Good luck!
• Big Damn Heroes: Asgore accidentally saves you from Temmie when they try and kill you, forced to flee when they hear him coming, and when seven of them try to gang up on you, Flowey pops up to defuse the tension by threatening to call Asgore on them. In Ruthless, the Temmie that didn't flee tries to kill both Chara and Flowey, only for the flower to effortlessly one-shot them with a pellet and knock them away. Flowey once again seems to do this when in the hotel attic on a Ruthless route, popping up just in time before some shadowy creatures could attack Chara.
• Big "SHUT UP!": The conversation with Papyrus after fighting Sans on a Ruthless route can result in Chara shouting one of these.
• Breaking the Fourth Wall: Papyrus and Sans at the end of the first demo's post-credits sequence, where Papyrus lampshades that people would've expected to encounter him instead of Sans (referencing how vanilla Underswap has Papyrus replace Sans in meeting the human first) and assuring fans that waiting for the full game to come out will be worth it.
• But Thou Must!: Played for Horror when Chara is scared by how they are railroaded into asking how to leave Ruined Home when they just want to stay.
• Chekhov's Gun: When Papyrus first demonstrates the use of the "MAGIC SPEEDY GOOP STUFF" he accidentally breaks through a wall, which he notes wasn't supposed to happen. You can use the goop to break through a crack in a wall later on.
• Cliffhanger:
  • The first demo ends with Chara leaving Ruined Home and being confronted by Crossbones, who either calls them "the bad guy", or says they will have a "bad time" depending on the route you're doing.
  • The second demo on the Compassion and Neutral routes have Alphys talking to Chara through a screen and warning them that she and the Royal Navy will be after them, before they head down into the mines. Taken further on the Ruthless and Evacuation routes, where Chara has to run from the Royal Navy, and as they reach the elevator to the mines, the rope holding it up gets severed and they end up falling.
• Cloud Cuckoo Lander: Possibly Chara. They can do some pretty odd ACTs with monsters (like Frisk), stack a glass of water and minimart items on top of their head instead of carrying them in their hands, and the Mad Dummy hears them mumbling their check of them if you choose to Check the Mad Dummy instead of saying goodbye in the tutorial, which could mean Chara is saying all their narration out loud under their breath.
• Combination Attack: A new gameplay feature—certain enemies can perform special attacks if they're encountered in the same battle. For example, a Loox taking a bite out of a Vegetoid and spitting the chunks at you.
• Cool Old Guy: Asgore, now a older boss monster wearing glasses and a little ponytail◊. He plays guitar as a hobby, is a Universally Beloved Leader to the monsters, and is a really gentle and sweet guy who just wants to take care of Chara. He is also still very much a badass.
• Corrupt the Cutie: Seems to be the case with Chara, influenced by LV and under the control of the player, in Ruthless.
  Checking the mirror: Never felt better.
• Death by Adaptation:
  • Frisk and Monster Kid, dead from events before the game by virtue of having their roles swapped with Chara and Asriel.
  • Can be considered Riverperson's fate as well, since they will be swapping with Gaster.
• Defeat by Modesty: To spare Aaxel, you need to have him flex his jacket off, ruining his "coolness".
• Demonic Possession:
  • Chara's dialogue options in Neutral and Compassion show they want to stay with Asgore and are confused and scared when the dialogue keeps changing to them pressing him on how to leave, with them trying to plead for help by the end. Regardless of whatever the possessing entity's intentions are, it's clear that Chara is frightened all the same.
  • This may be happening in Ruthless as well. Chara's face becomes shadowed like Kris' when we are controlling them, and this response on Tumblr indicates that the team sees the player as responsible for Ruthless, not Frisk. Since we are now controlling Chara, they may also be controlled by the player in-universe for Ruthless.
• Dies Differently in Adaptation: The fallen humans. In Undertale, their items were found in various locations with the inplications that they died there, or not too long after leaving those areas. Additionally, if a now-deleted post from Toby Fox is to be believed, they were all killed by Asgore. Here, the items are found in different locations, and so far they both have hints at how their owners died:
  • Chara finds the Justice SOUL's Cowboy Hat and Toy Gun in Ruined Home instead of the Patience SOUL's items, when in Undertale the Justice SOUL's items were found by Bratty and Catty in the dump at Waterfall. Obviously Justice didn't make it that far in their journey across the Underground in this world. Judging by the fact that the Toy Gun is found near a pile of rocks, it's likely that they died from a cave-in.
  • Instead of finding the Bravery SOUL's items, Chara finds the Dented Pan and Torn Apron in the Starlight Isles, when in Undertale they were found later on in Hotland. The Torn Apron being found in a well, along with some dialogue from a nearby Echo Flower, suggest that the Kindness SOUL died from falling into the well.
• Down the Drain: There is a mini sewer level under the City of Old, which Chara falls into and has to find a way out of. You also find the Toy Gun there.
• Early-Bird Cameo:
  • One of the other Temmies appears right at the start of the game, being the one telling the story of how the monsters were trapped underground.
  • Selecting the "Use" option on the Cell Phone will have Chara randomly dial numbers, sometimes resulting in responses from characters you don't meet until later.
  • The ending of each version of the demo introduces characters who will have a bigger role in the next area. The Demo V1 introduces Sans/Crossbones and Papyrus, while the Demo V2 introduces Sgt. Splosion and Admiral Alphys.
  • It's easy to miss, but Asriel can be seen at the festival in Starlight Isles signing comics with Papyrus and Crossbones, but his face is conveniently hidden by one of the arrows from the stand next to his. Since he has swapped roles with Monster Kid, it's likely he will make his first proper appearance in Crystal Springs.
• Even Evil Has Standards: Dying to Koffin-K will elicit this.

Koffin-K: This does not feel like victory... If this is a trick, this is TOO evil.

• Evil Versus Evil: Temmie wants to work with Ruthless Chara just like Flowey did in the original game, only here they find out a lot quicker that Chara isn't interested in being friends.
• Face Framed in Shadow: Chara's face becomes covered by a shadow once Ruthless is triggered, with their eyes hidden. In an aborted Ruthless run, Chara's eyes become visible again but their face remains eerily shadowed, creating the appearance of them having a Thousand-Yard Stare.
• Faking the Dead:
  • You can "kill" Mettalot, but it's blatantly obvious from what we know from the original game and what a show Mettalot puts on as he does it that it's just an act. In a Neutral run, he'll even tell you that ghosts are immune to your attacks, but in a Ruthless run, the journal will list him as dead even though he faded away rather than dusted, and you didn't gain any EXP from it, implying that Chara believes they really killed him.
  • In the Ruthless route, Sans/Crossbones quickly swaps himself out for a cardboard cutout when you're about to kill him. Despite this, Papyrus still thinks he's dead due to not having witnessed the fight, and Chara either thinks so as well, or just believes that his Crossbones persona is no more.
• Fandom Nod: During his Ruthless route fight, Crossbones will tell Chara a long, invested story about how he's a refugee from another world, empowered by a faulty experiment and his "relative", and seems to fight children at the end of every world he flees to, all in a clear reference to many popular Undertale fan-theories and fan-games surrounding Sans... before going off the rails and claiming that he's on the run from multiversal police, and he knows Chara's their agent. Then he drops the act completely, reveals it's from one of his comics, and admits that he told it to buy time for the evacuation, with Chara getting legitimately mad afterwards. It's an amusing way of calling to attention fan theorists and genuinely taking the player off-guard by drawing them into familiar theories and fan-plots and then throwing them out.
  • If you die after he finishes this story and come back, Crossbones instead spins a story about how he's actually from a planet populated entirely by Sans-es, where all they do is tell puns and perform stand-up comedy. He then goes on to say that there has since been a flood of people that analyze their every move, poring over everything he says and does trying to find meaning that isn't there and motives that don't exist, all while forgetting everything he actually meant. It's a funny story, and another play on some fan theorists: people who comb through the game for lore and information on Sans specifically, often to make fan content, all while misunderstanding his character and what he was trying to say in the original game.
  • If you die after he finishes that story and then come back again, Crossbones'll drop the act early when he sees it isn't working, and acknowledge that if you know that he's just there to buy time, then continuing to fight him is actively detrimental to your goal of wiping out the monsters, and the only reason you're still trying is simply because you want to beat him. He will call you out in a similar manner to the original game, but also comment on how you're just trying to get past him for the sake of it and aren't even having fun anymore, in what is possibly also a nod to how fangames will often put a ridiculously hard Sans fight in the way, which die-hard fans will persist and slog through despite having no logical reason to continue doing so. Not completely unlike what the player is doing right now.
• Faux Affably Evil: Temmie. They like to mess around by playing cute and dumb, but they're just waiting for the perfect time to drop the act and steal Chara's SOUL.
• Final Death Mode: Naming yourself "Death" will make dying result in the save file restarting from the beginning.
• First-Person Smartass: Team Switched uses the Narrator Chara theory from Undertale^note the theory that Chara's spirit is providing you/Frisk the flavor text and checks in all routes, but keeps Chara as the narrator for the game despite Frisk taking their place. As in the original game, Chara can get very snarky in their narration.
• Foreshadowing:
  • The opening of the game shows the backstory being narrated by a Temmie who doesn't look like the one you encounter at the beginning. That's because there's more than one of them.
  • When you first reach the area with the binoculars in Starlight Isles, if you look through them you'll see Harry, Larry, and Koffin-K talking to the Mad Dummy. You later encounter the Mad Dummy possessing a doghouse, saying they got it from the former three who claimed that it would help them get revenge.
• Funetik Aksent: As shown by one of the naming Easter Eggs below, Alphys seems to have a French or German accent that she didn't have in Undertale. It's implied by her dialogue on the naming screen if you name yourself "Alphy" that it's just an act, and confirmed in the Ruthless route where she drops it altogether.
• Glasses of Aging: The game's iteration of Asgore is given a pair of reading glasses to subtly indicate that he's physically aged compared to his canon counterpart.
• Guide Dang It!: While in Koffin Keep, you come across Bugerpant, who is surrounded by bats. Chara says that they could drive the bats away with a flashlight, so you'll have to look for one somewhere in the area, right? Nope. You should already have one, specifically the Bone Signal that Crossbones gave you earlier when you found him in disguise near the binoculars. It's easy to forget that you still have your Key items while in Koffin Keep, and unless you check the item, it's not completely obvious that it can function as a flashlight. If you didn't interact enough to recieve the Bone Signal, or if you leave Koffin Keep without helping Bugerpant and the gates close, then you're out of luck and don't get the I.O.U from him.
• Hello, [Insert Name Here]: We still get the opportunity to name Chara despite the role swap, and this time around it's a straight example because now they're unambiguously our player character, and it's justified by them losing their memories from the fall. Like Undertale, the game has some special responses to certain names. Here's a list.
• Horrifying the Horror: When Ruthless Chara makes it clear that they have no desire for a partnership, all but the un-shadowed Temmie retreats, who doesn't think that Chara's that bad. Had it not been for Flowey popping up, they might have regretted those words.
• I'm Standing Right Here: After leaving Starlight Isles, Chara comes across three Temmies on the bridge, talking about what to do with them. When they finally notice Chara slowly approaching them, they immediately stop talking and let them pass by.
• In Spite of a Nail: Even though the game takes place in an alterante universe where not only are the roles between certain characters swapped but the locations are completely different, some things are still similar or the same as in Undertale:
  • Even though Asriel is alive, Flowey still exists, with his origins being less clear.
  • Muffet has swapped roles with Grillby, but despite the latter not having a boss battle in Undertale, Muffet is still fought here.
  • Asgore is still the one who declared war on humanity, with the difference being that Toriel did not leave him after this even though she disagreed. The reason he's in Ruined Home now is because she exiled him there for deciding he no longer wanted to go through with the plan.
• Jerkass:
  • The Mad Dummy. They attack Chara no matter what they do during the tutorial, and even cause trouble for other monsters offscreen just to get Chara alone to attack them.
  • The Greasers, but specifically Aaxel, who goes out of his way to make Bugerpant's life hell for no reason other than believing that he's trying to make moves on Flara.
• Jerk with a Heart of Gold: Muffet. While she's much more snippy with Chara, it's mostly because of what happened to her. She still cares about her spiders immensely, and even grows to be kinda friends with them after a baking session lets her vent.
• Kick the Dog: Naturally, the Ruthless run has some rather cruel narration changes:
  • Checking the note by Asgore's toilet while on a Ruthless run has Chara call it idiotic drivel.
  • Chara calls Asgore's bed "a bed fit for a fool"
• Kidnapped by the Call: Happens to Chara in the Compassion and Neutral routes, with them forced by a force controlling them to leave a happy life with Asgore in Ruined Home.
• The Leader: Asgore. He may not be the official mayor of Old Ruins, but his unfaltering kindness in helping monsters with their problems, as well as said monster's makes him this.
• Leaning on the Fourth Wall: Muffet leans on the textbox during her hangout as she vents out her frustrations.
• Living Shadow: If you return to the sewer under the City of Old, you'll discover several shadow people on the walls. They're kinda creepy, but just as friendly as all the other NPCs.
• Marathon Boss: Just like in Undertale, Muffet's fight is this. Unlike the original game, though, Muffet's fight can't be skipped by eating one of the items from the Spider Bakesale. It does lower her ATK for the next turn, though.
• Monster Compendium: One part of the journal is dedicated to the monsters that are encountered in the game, with the information changing depending on what you do. For example, if you flee from the first type of enemy you encounter, there won't be much information until you encounter another one and don't flee from it right away, and if you're playing a Neutral run then any monsters you kill will have their status as "killed", but if you're doing a Ruthless run it will instead say "eradicated". Some monsters that aren't fought when you first meet them (or even at all) will also have entries added.
• Mythology Gag:
  • The Mad Dummy takes a few cues from Undyne in Undertale, making Chara fall off a bridge in Ruined Home and chasing them with projectiles in a Call-Back to Undyne chasing Frisk with spears and making them fall off a bridge in Waterfall. They are also just as unreasonable in hating Chara no matter what they did in the tutorial, the same as they were with whatever Frisk did in the tutorial with their cousin and like Undyne justifying her attacking Frisk with different excuses depending on the route.
  • In the City of Old, Asgore owns a flower shop named Flower King like in Deltarune.
  • Selecting the use option on the cell phone has a few secrets from dialing random numbers, one of which is the "Hotline for Idiot Babies", also from Deltarune.
  • Chara's shadowed face in Ruthless might reference up to three! Their face is hidden this way in flashbacks showing them from the front in Undertale, in the debug build of Undertale there exists a sprite that looks like a cross of Frisk and Chara with a shadowed face who you can make show up instead of Frisk's reflection,^note Especially interesting considering the run this shows up in for TS!Underswap is that the debug build sprite is commonly theorized by fans to have been a scrapped feature where Chara (or this faceless mishmash of Chara and Frisk) would've replaced your reflection after you completed Genocide and sold Frisk's SOUL and Kris has an almost perpetually shadowed face when you're controlling them in Deltarune.
  • When fighting Asgore on a Ruthless run, his final attack is taken from one of Toby Fox's earlier ideas as seen in the artbook, as is the terrifying face he makes during it.
  • The area where you fight Crossbones has his logo on the ground, clearly based on the boss rooms of King and Queen in Deltarune. There's even a stray pixel!
  • In the room before the Guiding Light festival, there's a broken piano. Interacting with it four times will result in it playing a very familiar four notes.
• Never Trust a Trailer:
  • The UNDEREVENT 2023 trailer that shows previews of events that happen in Starlight Isles has Chara wearing their normal outfit while at Koffin Keep. In the actual game, they get forced to wear a different outfit until after they've completed their tasks, by which point they'll have Koffin-K on their head until after they've left.
  • As part of the Running Gag with Undertale's trailers and those of a few other fangames, one scene in the Demo V2 trailer shows Chara jumping between platforms in Hotland (only with mushrooms instead of steam vents), with a note saying "(This isn't in the game)".
• Nightmare Face:
  • Temmie follows in Flowey's footsteps by busting out a few of these, complete with evil cackling.
  • Asgore makes a scary face during his final attack on a Ruthless run, as a reference to one of Toby Fox's original concepts.
  • Muffet makes a particularly creepy face at some points during her boss battle.
• No-Gear Level: Koffin Keep. When Koffin-K makes Chara into his servant, they're forced to wear a different outfit and lose all their items except for their Key items. Thankfully, there's only one battle before you get the items back.
• Nonstandard Game Over: Dying to Crossbones in Ruthless will have the usual Game Over music be replaced with something sillier, while a screenshot of the moment you died is shown as a photograph, with Crossbones commenting on it.
• Not His Sled: Even though TS!Underswap is a different portrayal of Underswap than usual, it still uses mostly the same swaps and follows a similar story structure to Undertale thus far. Because of this, when the game doesn't do something from the original game (or Underswap), it tends to be a Plot Twist—for example, there are still multiple Temmies, and Flowey is still an individual character (independent of Asriel this time).
• Obfuscating Stupidity: Temmie, who puts on a show of acting as ditzy and silly as an Undertale Temmie to lure victims into a false sense of complacency and toy with them.
• Oh, Crap!: Almost every cutscene in Starlight Isles while on a Ruthless Run involves one monster or another having this reaction to Chara. Even Koffin-K.
• One-Time Dungeon:
  • Once you leave Ruined Home, the door locks behind you so you can't go back. It's likely that, like in Undertale, you won't be able to go back there until the ending.
  • After you leave Koffin Keep, the gates will be closed, although it's possible that you might be able to revisit there in the future.
• Or Was It a Dream?: If you take another nap in the bed when Asgore is in the garden. Chara's narration states that the next day, they woke up to Asgore bringing them a slice of pie and they spend the day together comfortably, but Chara describes still feeling compelled to leave. Chara then wakes up and everything is the same as you left it, with Asgore still out in the garden. It's never explicitly said to be a dream, but given that Asgore doesn't reference the day Chara described (and he isn't able to bake pies without burning them), it was probably just Chara dreaming.
• Permanently Missable Content: The I.O.U that you recieve from Bugerpant if you help him in Koffin Keep, a place which becomes inaccessible after you leave; you need to use the Bone Signal that you recieved from a disguised Crossbones near the binoculars you went past earlier, which itself can be missed if you don't interact with him enough in that area. What makes it even more annoying is the fact that Chara's dialogue makes it seem as if you have to go looking for a flashlight somewhere in Koffin Keep, it's easy to forget that you still have access to your Key items, and you also might not have checked the Bone Signal and seen that it's a flashlight, making it much less obvious what you have to do.
• Please Wake Up: Inverted if you kill Asgore normally. To protect Chara from knowing they killed him, he tries to pretend that he's just tired and going to take a nap, but his updated status in their journal after his death shows they know he's dead.
• Recurring Boss: Downplayed with the Mad Dummy. We haven't actually fought them yet (unless you count the tutorial), but they reappear to chase Chara through the sewers in Ruined Home after breaking the bridge, and they later make a deal with Koffin-K to possess a doghouse and chase Chara again in the Starlight Isles.
• Red Eyes, Take Warning: Blink and you'll miss it, but when Chara is getting up after falling in the beginning, there's a moment where only one eye is visible and it's bright red, reminiscent of their canon counterpart's eyes glowing red in the Soulless Pacifist ending and Kris' eyes being red in Chapter 1's ending for Deltarune. Once Chara straightens up, they have normal dark brown eyes for the rest of the demo.
• Seasonal Baggage: Undertale's four main areas seem to be themed around the four seasons, the Ruins fitting for Autumn, Snowdin being Winter, Waterfall being Spring, and Hotland being Summer. Team Switched shifted the seasons assigned to each area, so "the Ruins" swapped seasons with "Waterfall" and "Snowdin" swapped seasons with "Hotland". Ruined Home (the equivalent to the Ruins) is now Spring with golden flowers and lush greenery growing everywhere. Starlight Isles (the replacement of Snowdin) is now Summer with a lava pit far below, while up above (the explorable area you traverse) the heat manifests as dark wooded areas teeming with trees, mushrooms, flowers, and wildlife evoking warm nights at summer camps (with Muffet and her spiders in turn redesigned to be "Spider Scouts"), and bodies of water and pirate themes to bring to mind the tropics. Crystal Springs (the equivalent of Waterfall) will be Autumn, and Boreal Bluffs (the replacement of Hotland) will be Winter.
• Shout-Out:
  • Team Switched borrows the name Mettacrit for Mettaton's name as a ghost monster from Storyshift^note Which itself is a Shout-Out to the game review website Metacritic. Since Voltrathelively gets credited for it in the demo's credits and even listed as a playtester for the demo (as Voltra), it would seem they had the creator's blessing.
    • However, Mettacrit’s name was later changed to Mettalot, as Team Switched wanted to disassociate from Storyshift and give their take on Mettaton a unique name.
  • Naming Chara "Clover" will cause them to ask if you are ready for justice.
  • Mettalot's design◊ shares certain similarities with the Ghost type Pokémon Misdreavus◊.
  • The Mad Dummy's first appearance is heralded with the word "DUMMY!!" appearing across the screen as an Unsound Effect, a nod to the ゴゴゴ text in JoJo's Bizarre Adventure.
  • The Game Over screen is a homage to EarthBound, with the protagonist lying in a beam of light and the game calling their death "a bad dream".
  • The song "A Place To Call Home" uses instruments from The Legend of Zelda: Ocarina of Time.
  • Norman's name and true nature might be a reference to the first episode of Gravity Falls.
  • The welcome mat at the office in the City of Old has the Sburb logo on it.
  • "Fuzzy Friend", Temmie's Leitmotif, contains references to "Temmie Room" and "Lonely Girl's Room", two songs from the real Temmie Chang's short game, Escaped Chasm (which Toby Fox also made the music for).
  • In Sans's hangout, there are about three references to the movie Morbius in it, albeit the references are based on the memes.
    • If you talk to Sans a few times after the hangout place, he'll say his favourite part of the hangout was when he said "It's hangout time" and hangouted all over the place.
    • Talking to Koffin-K twice has him get one of his bats to lift him up from the coat rack, while yelling "IT'S KOFFIN TIME!" Only to shortly be put back on the coat rack after by Sans.
    • If you leave and come back, there will be a tape in the punishment shack, apparently containing the film "Koffius." Sans loves this movie, much to Koffin-K's displeasure.
  • In the Sans fight on the Ruthless Route, checking him after he dodges calls him "a moving target".
• Sitcom Archnemesis: The Mad Dummy acts this way with Chara, hamming it up about how despicable Chara is and attacking them regardless of what they do in the training segment.
• Spared by the Adaptation:
  • Chara and Asriel aren't dead in this world, with Asriel even grown into a young man.
  • Likely Gaster, who will be swapped with Riverperson and probably avoid his counterpart's fate of being scattered across time and space. Possibly not though, as selecting his name still crashes the game.
• Stalker without a Crush:
  • The Temmies stalk Chara around the Underground, intending to kill them and steal their SOUL. Unlike with Flowey in vanilla Undertale, this isn't limited to catching them moving out of view upon backtracking back to the entrance of a room and they'll sometimes appear in plain sight too while exploring.
  • Mad Dummy is also implied to be stalking Chara and waiting for the right chance to get revenge against them, as there's a secret in Asgore's bedroom where if you interact with the guitar enough times, it's implied that they're possessing it in order to watch them in secret.
• Stealth Pun: The Canine Unit of this game instead of being members of a royal guard with a medieval theme, are instead members of a royal navy with a sailor theme. One could say that they are; sea dogs.
• The Stinger:
  • After the credits roll in the Demo V1, you'll be treated to a sneak peak at the next area, Starlight Isles—after wandering through a forest, Chara finds themself cornered by Sans (in his Crossbones persona). The scene then ends, with Sans and Papyrus providing some fourth wall-breaking commentary on the scene and telling the player to wait for the full game.
  • After the credits in the Demo V2, Flowey will pop up and comment on Chara's descent into the Crystal Springs Mines, while also telling the player to wait for the full game.
• Story Branching: According to Team Swapped's May Progress Report, there are four routes instead of three.
  • Neutral, when you only kill when necessary.
  • Compassion, when you chose not to fight and spare everyone.
  • Ruthless, when you exhaust the kill count in Ruined Home.
  • Evacuation Neutral, when you exhaust the kill count in Ruined Home, but spare Asgore or anyone else after that point, or exhaust the kill count in only Starlight Isles.
• Stupidity Is the Only Option: In the room where you fight the Ruined Knights, there is a bridge with a sign that refers to it as the "human capture bridge", and each end of it has deactivated spikes. It's obvious that as soon as you step onto the bridge, the spikes are going to activate and trap you, but there is no other way to proceed.
• Team Dad: Asgore to all the other monsters in Ruined Home, who talk about him in glowing terms. Judging from the graffiti NPC's comments and the phone call you can make to him about the Greasers, he also seems to have a hand in keeping the younger monsters on the straight and narrow. Bugerpant lampshades this trope, saying he's like everyone's dad and telling Chara to be good to him.
• Totem Pole Trench: One of the Greasers, Norman, is quite obviously this. Specifically, he's a Froggit, a Whimsun, and a Loox, as foreshadowed by his attacks in battle. You can spare him by revealing this, making him run away, and his components can be talked to at Grillby's after.
• Universally Beloved Leader: All the monsters in Old Ruins love Asgore for helping them with their daily lives. When a monster attacks you when he's around, Asgore will simply say hello and tell them that he's in the middle of something with Chara, with said monster apologizing and going away.
• Video Game Caring Potential: While exploring the City of Old, there are various sidequests you can do for a small reward, such as watering a plant and helping to clean up a messy office. Completing them can feel satisfying.
• Wham Line:
  • After finally reaching Asgore's home, when Chara goes up to talk to him, they find their dialogue is being overwritten.
    I didn't say that.
    What's happening?
    Help me
  • Done after reaching the end of Ruined Home, where you encounter Temmie again;
    Temmie: Don't worry! I have some "friends" of my own!
• Wham Shot: Immediately after Temmie's Wham Line, Flowey pops up in the middle of the scene, looks around casually at Chara and all the Temmies, and quips, "Am I interrupting something? You seem kinda... busy." No one predicted Flowey appearing in Ruined Home, and especially not that he'd have the major role implied for this AU!
• Wraparound Background: The room in Ruined Home where Asgore talks to you while the two of you walk has this to prevent you from reaching the end of the room without seeing all of his dialogue.
• You Remind Me of X: Asgore comments on a spark of adventure and curiosity in Chara's eyes, starting to say it reminds him of someone before trailing off. Since he compared the hope in Frisk's eyes to Chara's in Undertale, he's likely thinking of Frisk here.

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