The Pacifist Musical
- It's hard not to get a little teary-eyed at "Once Upon a Time," especially if you're a huge fan of the original and already know the story back-to-front.
- Most of Toriel's songs fall into this category. "Home" is a rather loving song, but it feels very bittersweet at the same time, knowing that right after this song, as in canon, Frisk asks to go home. This is followed by "Heartache", where she pleads with Frisk to go back upstairs, worried about the child's safety. The first reprise of "Fallen Down" has the two saying goodbye to each other, and Toriel's voice, especially near the end, sounds heartbreaking. "Reunited", which is partially a reprise of "Home", is more of a happy tear-jerker.
- The final version adds a non song one: when Frisk leaves the Ruins and is locked into Snowdin, they try to call Toriel and get no answer. While this is the case in the game, its placement comes off as quite tragic.
- "For the Fans (To the tune of 'Oh! My One True Love')" Following the upbeat, bombastic, high-energy performance of "Death by Glamour", 'For the Fans' is both a Crowning Moment of Heartwarming and a Tear Jerker. Following Napstablook expressing their dismay and heartbreak over Mettaton announcing to the entire Underground his upcoming departure, each and every monster starts singing their hearts out to him about how much he's meant to them over the years - how much joy he gives to their lives as their number 1 (and only) entertainer. Mettaton himself sounds like he's on the verge of tears as he admits he's dedicated his entire life towards being a good entertainer and the Underground has tuned in to every one of his performances. Leaving would break so many of his loyal fans' hearts and concedes that he won't be making his surface debut yet to make his fans happy, and because his Android form drained his batteries.
- "Undertale". While in the game, the story of the Dreemurr family meeting Chara, followed by their family tragedy was told second-hand by a group of monsters, here it's actually shown in a flashback. Just like the story in-game, it starts out sweetly, but then takes a turn for the tragic. The way Chara and Asriel's voices break as they're dying really sells the suddenness of their deaths, and the art features such images as one of the human villagers impaling Asriel, followed by Asriel turning to dust in his family's garden.
- "An Ending". In-between the segments where Frisk's friends leave a message for them, the monster chorus sings a song wondering what's going to happen in the future; the fallen child has escaped, the other human souls have disappeared, the monsters have resigned themselves to staying underground for a longer time, possibly forever, and to top it all off, their king is dead.
- Once we rejoiced/Found the power in our voice/Cheered the human on/Now they're gone
And now we sing/A dirge for our lost king/'Neath the mountain he/Will stay...
- "His Theme". It starts with Asriel singing about how he thinks he's beyond forgiveness, and he begs Frisk to just leave. Frisk insists on staying, vowing to be his friend and show him love; meanwhile Asriel initially tries to reject this, but eventually accepts Frisk's offer of friendship.
- If you thought Frisk hugging Asriel in the game was tear jerking enough, in the musical we get to hear Frisk start to cry as well, and they end up being the one saying "I don't want to let go" instead of Asriel.
- The fight with Asgore, as in canon, especially with the powerful music and Asgore's mournful lyrics. This is the fate of the entire world that's at stake here — and no one involved wants to fight.
The Genocide Package
No surprise that the Genocide Package is loaded with Tear Jerkers:
- "Ruined". Considering the subject matter, it makes sense, but it's still hard to hear the monsters' final cries as they die at the hands of what could have been their savior.
- "DeTermination". It covers Toriel's death in the Genocide Run, with her realizing just how horrible this human she found is. The loss of her faith in them combined with her oncoming death makes it arguably even more devastating than her death in the game; since she shows no sign of the Laughing Mad state she falls into there. Instead, she slowly breaks down into horrified tears, audibly sobbing as she sings her final lines.
- During the sequence, it also shows the images from the Pacifist version of these moments; but corroded into sepia to show that all of that has been lost. For bonus tearjerker points, many of those scenes play out the same way in the game proper whether you're going Pacifist or Genocide, meaning Toriel could be lamenting on how the kindness she showed Frisk in this timeline turned out to be for naught.
- The final image she flashes back to at the end of the song, as she's cursing Frisk's determination? Instead of anything with Frisk, it's Toriel and Asgore watching Asriel die and crumble to dust in their garden. Toriel just wanted to love Frisk like they were her own child, only for this one to viciously murder her without a care despite being offered a loving hand by her; in turn becoming more like those who killed her own biological son.
- "Papyrus Believes In You". Papyrus's death, after he spends the bulk of the song compassionately singing about how Frisk can be better than they are. Despite clearly being scared out of his wits, he stands his ground; showing no anger or malice whatsoever for Frisk's previous crimes, and offering to be their friend and guide while helping redeem them, as per his beliefs that everyone can be good deep down. The kicker is the final part; it appears to work initially, with Frisk going over to Papyrus, appearing to want to hug him... only to then attack him the moment Papyrus drops his guard. Even more so is the utter distress and fear in Papyrus's voice after he's reduced to just a head — combined with the music switching from a slowed-down version of Snowdin's music to the Genocide version of "Bonetrousle" — and even after being decapitated, he still believes Frisk can change.Papyrus: (audibly terrified) W-well... that's not what I expected. B-but... st... still! I believe in you! You can do a little better... even if you don't think so! (quietly sobs) I p-promise...!
- Not to mention the horrible CRUNCH when Frisk, per common fanon, finishes him off by stepping on and crushing his skull under their foot; right as it happens, you can see tears in Papyrus's eyes.
- In "Evacuate" we see the remaining monsters accepting their imminent oblivion. Their only way to see the Sun might be in death, and that they are well aware that they have no chance against the human — but some of them try to fight anyway so that they can buy time for their remaining friends/family to evacuate and escape from the genocide. There's also Alphys pleading with the monsters not to look back or dwell on the fact that they'll never see their friends or home again — she tells them to just run.
- While "Power of NEO" is more of a Moment of Awesome, some parts are punctuated with a chorus similar to "Death By Glamour", but the lyrics are blurry. Which might be confusing until you remember the scene in "DeTermination" where Toriel is surrounded by the spirits of the dead Ruins monsters singing their own chorus, at which point you realize the blurred chorus lyrics are Mettaton's now-dead fans.
- By extension, Mettaton's normally-unshakable confidence waning over the course of the song; going from being so sure of stopping Frisk's rampage with his NEO Mode ("Saving the Kingdom from the fallen child of man, others failed to stop you, but I know I can!") to slowly realising that he cannot ("If this is the last time we meet, then I shall accept my defeat..."), ultimately accepting his demise and sacrificing himself to hold Frisk back for as long as he can ("And so let no one say I was a coward and I didn't save the day..."), and buy time for Alphys and the remaining monsters to evacuate. The fact that NEO legitimately puts up a fight before he falls in this adaptation makes it even more poignant.
- His death in itself counts as well. It starts out with Mettaton NEO starting his non-Genocide monologue, where he comments that Frisk was holding back and is "not absolutely evil"; smiling through his suffering when he considers the possibility that his sacrifice is not in vain and that Alphys and the remaining monsters will be safe. It's right at this moment when Frisk cuts Mettaton NEO off with another jarringly-loud slash; whilst his last words after this should be Narm, NEO's shaky, exhausted delivery and loud cry of agony as he's struck down makes it both scary and surprisingly sad.
Mettaton NEO: G-guess you d-don't want to join... my fan club? - In "Floweytale", Flowey tells Chara all the details of his past; what he did as a flower, how he tried to feel love, and how he exhausted seemingly every possibility in his desperation to feel something. At the end, right when Flowey realises that he himself is not safe from being killed, we see Chara looming over Flowey with a berserk smile; the flower cowering in the Fallen Child's shadow with a look of absolute terror.
- "Star" portrays Chara as a Fallen Hero. They were a young kid who genuinely wanted to save the monsters and treated them with kindness; only to badly screw up with the plan that got both them and Asriel killed, leading to everything going horribly wrong. Because of this, they became a bitter shadow of their former self; eventually coming to the grim realization that, with basically everyone they once knew and loved now dead, all that's left for them is to finish destroying everything and fully embrace their destiny as the Angel of Death.Chara: (on the verge of tears) No hopes, no dreams, I have nothing... death is all that can define me. The end's calling, no more stalling. Stars will fade, but I'll keep shining.
- While "Megalovania" manages to be both Awesome and terrifying, the deaths of his brother and friends have basically pushed Sans into some sort of psychological breakdown, and it shows in his voice; unpredictably jumping all over the place in octaves and moods, between Tranquil Fury and full-on Unstoppable Rage. He also laments how he thought Frisk could be better, only for it to turn out horribly. To cap it off, the lyrics all but outright state that Sans remembers the True Pacifist endingnote , and once Frisk eventually lands the killing blow, we see several rapid-fire flashbacks of the time they spent together during said pacifist run in the background.
- "But Nobody Came", the final song of the package. Before the song proper, we get the scenes of Asgore and Flowey meeting their ends, with loud, jarring sound effects to bring the point home that these two were murdered. The song itself is a slow, solemn dirge as the now-dead monsters sing about how there is no more hope and their world is nothing more than death and despair, since no one came to save them.
- Even worse is Flowey's death. Right before the Fallen kills him, you can hear him drop his usual squeaky tone; and for a second, he speaks in Asriel's voice.
Flowey: I can help! I can... I can... (as Asriel) Please! Please don't kill me! Please-!- Worst of all is when the Fallen — not Chara, the Fallen — appears in the darkness, and all but outright tells the viewers that the reason the Genocide route even occurred is because they wanted to hear Megalovania.
The Fallen: (in an echoing, demonic hiss) Together, we eradicated the enemy and became strong. We sang about it. We celebrated their deaths. With views. With comments. With likes. With shares. With subscriptions.
Other
- After the Genocide Package was fully released, one more song came out a week later: "Entry Number 17: Dark, Darker, Yet Darker". Like "Megalovania", it manages to be both Awesome and creepy, but there are still a couple tear jerkers slipped in. Gaster has not had a pleasant existence in the void. Not only that, but the song goes with the WMG that Sans and Papyrus are the sons of W.D. Gaster, who mentions an intent to avenge them. Finally, at the very end, when Gaster kills the fallen child, he admires their determination before musing that it would have been nice for him to have some when it mattered — presumably when he fell into the CORE or when the fallen child was killing everyone. Possibly both.
- The fact that Gaster was essentially Forced to Watch his own children get brutally murdered and was only able to do something long after their deaths.
- As Ralsei attempts to encourage Kris that the choice is theirs in "Field of Hopes and Dreams," Kris dejectively references the SOUL's control over them, believing that as long as they're under its control, their choices don't matter...