You are Miss Pauling, sent on a mission to the Badlands to kill Redmond and Blutarch Mann. On the way, however, your motorcycle falls off a cliff, and you end up in the BLU Medic, Sani's, hospital, recovering. From there, your goal is to make it to Mann Co. headquarters, and get past both the RED and BLU mercenaries to kill the two Mann brothers.
Overtime contains examples of:
- Adaptational Nice Guy: Most of the mercenaries are a whole lot nicer than they were in TF2, but some standout examples are:
- Sani, the BLU Medic, is much kinder than the original was, saving you from Ballooney and healing you back to normal for no reward. However, Eli, the RED Medic, is just as creepy and sadistic as usual.
- Sniper flat-out refuses to go through with killing you after a while, saying that he can't bring himself to do it.
- Adaptational Villainy: The Pyro is Obliviously Evil in TF2, but a gigantic, monstrous abomination in the afterlife, serving as a Photoshop Flowey replacement. This eventually gets downplayed after his defeat, when he reverts to a regular human and is revealed to just be very childish.
- Adaptation Personality Change:
- Dell, the BLU Engineer, acts like Sans in most respects.
- Scout is a big example. While he's a cocky Jerkass in the original, here, he's a loner who acts out due to having no real friends on the RED team, and is a lot more emotional than usual.
- Misha, the RED Heavy, is quiet and solemn, and regrets having to fight you in battle. This is a stark contrast to his Boisterous Bruiser self in TF2.
- Body Horror: Most of the Experiments locked up in Eli's basement have extremely disturbing designs, just like the Amalgamates.
- Bottomless Magazines: Played straight by your Derringer and most enemy weapons, but averted by Jane's rocket launcher. At the end of the fight, he surrenders when he runs out of rockets.
- Chekhov's Gun: On the Genocide path, Spy drops a Sapper when you defeat him. This Sapper is vitally important to defeating Dell, and the game is Unwinnable by Design without it.
- Cloudcuckoolander: Jane, the BLU Soldier, is completely unhinged, just like Papyrus and his canon self.
- Composite Character: The TF2 mercenaries and other characters combine traits from their canon selves and the Undertale characters they replace.
- Destructive Teleportation: The save points in this game are teleporters that Dell uses. They can save someone's person, and can also copy them elsewhere whilst annihilating the original self. Dell has felt brief moments of oblivion many times this way, but Ms. Pauling cannot teleport because her prosthetic heart prevents her from truly dying.
- The Dog Bites Back: If you spare Scout, then he beats up Eli off-screen at the end of Dustbowl.
- Easy Levels, Hard Bosses: Just like Undertale, though easier overall. The regular enemies are very easy, while the bosses, while not too bad, present the real challenge.
- Face–Heel Turn: Played for laughs by Ballooney in the True Pacifist ending. Once he's helped you get through it, he mocks you for having trusted him, and reveals his secret plan... to steal all of your money and use it to buy booze.
- Final Boss: Like Undertale, each route has a different one. It's Pyro on Neutral, a Boss Rush of every mercenary in reverse order on True Pacifist, and Dell on Genocide.
- Fun with Acronyms:
- Like with Undertale, a commonly-used term in the game is actually an acronym: DMG, or Depression MaGnitude. A person with 1 DMG is slightly upset, while one with 5 DMG has a death wish caused by grief, and it affects how much they can put themselves into harming you. Most enemies have 2-4 DMG, but Dell is the only one to have 5.
- Miss Pauling's LV is for LeVelheadedness; every time a mercenary is killed, she gains more of an understanding of how you're unwittingly using her prosthetic heart to possess her, and shortly after her LV is high enough, she destroys the heart to escape your grasp for good at the end of the Genocide route.
- Graceful Loser: Sniper and Spy both accept defeat gracefully if they're killed.
- Grievous Bottley Harm: How Ballooney attacks you in the prologue, and how he finishes off Misha. Averted by the bottles he throws at you in the Pyro fight, which heal you.
- Heroic Suicide: If you complete a Genocide run, Miss Pauling finds out that her prosthetic heart lets you control her body, and she takes her own life to stop you.
- I Surrender, Suckers: Dell actually subverts this, as if you accept his offer of mercy, he lets you go on, and even encourages you to save. It's a lie. If you continue, you'll find a room full of Sentry Guns waiting for you, forcing you to do your run all over again if you saved.
- Jerk with a Heart of Gold: Ballooney violently attacks you in the prologue, but apologizes for it later, claiming that he gets violent when drunk. He later comes to help you in the Neutral and True Pacifist endings, and his kinder side really shows in the Neutral ending when he comforts the defeated Pyro and holds no hard feelings over how Pyro's treated the other balloonicorns.
- Kaizo Trap: Dell can still kill you even after he uses his special attack, if his sentry's bullets hit you.
- Karma Houdini: On the Neutral and True Pacifist paths, Eli ultimately gets off scot-free for creating the Experiments. This is not the case on Genocide — unlike with Alphys, you actually get to kill him.
- Karmic Death: In TF2, Spy has to disguise to fool enemies into trusting him, then stab them in the back. Here, to kill Spy, you have to pretend to want to spare him, then shoot him when his guard is down.
- Missing Secret: After the Hidden Lab is cleared, Eli calls you, asking if you found all four Experiments... only to notice that only three of them are there. Who or what the fourth one was is never revealed.
- Nice Job Breaking It, Hero: If you decide to reopen the game at the end of the Neutral path, Ballooney reveals that you did this. He crashed the game to save you from Pyro, and by going back in, you ended up vulnerable to it anyway.
- Non-Standard Character Design: Like Photoshop Flowey, Pyro is made up out of real images of a gas mask, a fire-retardant suit, and gas canisters.
- The Nothing After Death: In Dell's fight, he reveals that "a black void" all that awaits after death, which he learned due to the split second of death caused by using a teleporter. As a result, he's not afraid to die.
- Shout-Out:
- Some references to other TF2 content creators are present. Irate Sven references ArraySeven, and the Weird Wizard references Muselk.
- Other enemies reference other Valve games. Confused Stan references The Stanley Parable, while the Physical Physician references Half-Life.
- The Cackledemon enemy is a reference to Doom's own Cacodemon. You can also find Doomguy himself in Dustbowl, lamenting the damage to the environment caused by radioactive waste in the same terms he used in the comic book.
- Slasher Smile: Sani gives you one if you kill him while you're on a Genocide run.
- Stable Time Loop: What you end up creating in the True Pacifist ending. You shoot the wheel of your own motorcycle, causing your past self to plummet into Sani's hospital.
- Stalker with a Crush: Scout acts like one while he's trapped in the Dispense-o-matic 9000. He later regrets it.
- Too Dumb to Live: On the Genocide run, Tavish takes some special pills that Eli gave him, claiming that they'll make him stronger. It looks like he's going to turn into an Undyne the Undying equivalent... but then he dies, due to taking pills with alcohol.
- Unskilled, but Strong: Misha has a massive amount of HP, hits hard, and fires hundreds of bullets from his minigun every time he attacks, but he only has three different attack patterns.
- Villain Protagonist: Technically so on the Neutral run, since your mission is to kill Redmond and Blutarch Mann, and the other mercenaries are trying to stop you. However, it only really becomes notable on the Genocide run.
- Wake-Up Call Boss: Like Papyrus before him, Jane serves as one, being the first boss to change your color and use more in-depth attacks. Unlike Papyrus, he's also perfectly capable of killing you. His color mechanic makes you constantly bounce so you have no control over your air time, which can be disorienting to those expecting a Papyrus-style gravity mechanic.
