History YMMV / UndertaleTheMusical

** Although it had been foreshadowed a bit beforehand (Alex being notably open to covering the game on social media and later doing a few livestreams of it), ''[[VideoGame/UndertaleYellow|Decibat]]'' getting his own lyricized version of "Fever Pitch" was quite a surprise, signaling that his game would also get covers despite being a fanwork.

** Although it had been foreshadowed a bit beforehand (Alex being notably open to covering the game on social media and later doing a few livestreams of it), ''[[Undertale Yellow|Decibat]]'' getting his own lyricized version of "Fever Pitch" was quite a surprise, signaling that his game would also get covers despite being a fanwork.

* HeartwarmingInHindsight: Following the release of fellow fanwork VideoGame/UndertaleYellow, [[spoiler:Many viewers returning to Your Best Nightmare noted that the yellow soul's extended solo was made all the more meaningful with Clover's story in mind.]]

** One of Alphys's first mentions of Undyne is in this rather... weird line: "Sometimes when I watch anime, and I feel like I need to do something with my hands, I doodle pictures of Undyne in my notes, and...". [[ADateWithRosiePalms Yeah...]] Probably unintentional, but still rather jarring.

** During Hopes and Dreams, one of [[spoiler: Asriel's]] lyrics is "Chara, you'll be mine!" One of the top comments then asked [[InterspeciesRomance "Is he trying]] [[NotBloodSiblings to date her?"]] (Note while the initial comment on the video referred to Chara as "her", Chara's gender in the musical itself is left ambiguous regardless.)
** One of Alphys's first mentions of Undyne is in this rather... weird line: "Sometimes when I watch anime, and I feel like I need to do something with my hands, I doodle pictures of Undyne in mu notes, and...". [[ADateWithRosiePalms Yeah...]] Probably unintentional, but still rather jarring.

** Another special mention goes to [[spoiler: "Dark, Darker, Yet Darker", as at one point the Fallen is basically flung through ''several dimensions with different art styles'' before landing on Frisk's sprite from the game proper--which then shatters into pixels.]]

** "Fallen Down" is a very gentle, soothing melody, almost like a lullaby, which fits Toriel perfectly.

** [[spoiler: Dark, Darker, Yet Darker]] is an epic GrandFinale to send off the [[spoiler: Genocide Package]] with a bang, and boy it does so.

*** "[[https://www.youtube.com/watch?v=4WQyBHdcTdY The World Revolving]]" fits [[spoiler:Jevil]] to a ''tee'', being chaotic, complete with a dark reprise of "Don't Forget" from the actual game, with binaural audio to top it off to mimic the effect of the singers circling around you. Oh, and then there's the numerous references to [[spoiler:"Entry Number 17"]].
*** [[https://www.youtube.com/watch?v=iBV7MGcVDek "Field Of Hopes And Dreams"]] is a beautiful duet(?) between Kris and Ralsei, with Kris expressing their fears over their lack of agency and Ralsei trying to support them and keep their spirits up.
*** "[[https://www.youtube.com/watch?v=6az6uoq2sV4 Attack of the Killer Queen]]" perfectly fits Queen's personality as a non-malicious villain who seeks to enslave the Lightners for selfless purposes, along with her signature sense of humor and casual attiude, and Lulu Grey has a beautifully regal voice & even manages to hold notes for incredibly long times.
*** [[https://www.youtube.com/watch?v=KYdKDGq_1Cw BIG SHOT]] somehow manages to be ''even more insane'' than the ''Music/JunoSongs'' version, giving Spamton two voice actors (Juno and Tom Previte) in one fast-paced, chaotic, ReferenceOverdosed song. Naturally, it fits Spamton perfectly.

** Over the remade "Bonetrousle." Some liked the new one with original lyrics, as it fit the story better than the old version. Others, however, would rather they have kept that old version, the repurposed "Papyrus Makes a Mixtape."

* CantUnhearIt: Many of the comments from viewers have been about this trope, saying that the actor's version of a certain character is now the only way they'll ever be able to hear this character from now on. Undyne, Papyrus, and Mettaton, especially, get this a lot.

* GeniusBonus: [[spoiler: "The call of the void", name-dropped by Gaster at the end of "Dark, Darker, Yet Darker", is the translated term (the original is the French "L'appel du vide") for the desire to do something self-destructive, such as jumping off of a cliff or driving into traffic, even if you don't actually want to die.]]

** [[spoiler:The six human [=SOULs=] don't even get a full song, only getting the last part of "Your Best Nightmare", but they proceed to completely steal the show with what little time they get.]]

** 'But Nobody Came' has been released, the Genocide package is done with, right? [[spoiler: Nope. A week afterwards, Man on the Internet released ''Dark, Darker, Yet Darker'', starring ''[[DummiedOut W.D.]] [[GlitchEntity Gaster]]''. Suffice it to say, ''no'' one was expecting that.]]

* UncannyValley: Some of the drawings of Frisk just look... ''wrong''. Special mention to "Papyrus Believes In You", the first time we see Frisk's face in the Genocide Package; they've been compared to ''Slenderman.'' However, this may be intentional especially in the Genocide package, as it's mentioned by many characters that killing monsters and The Fallen's subsequent possession of both Frisk and Chara (as shown in Star for the latter) make Frisk look... not human.

** Not that Undertale the Musical. [[labelnote:Explanation]]This Undertale the Musical shares its name with [[https://youtube.com/watch?v=MobkO51msMI a different Undertale fanvideo]] also called Undertale the Musical, AKA Story of Undertale, which has a [[SoBadItsGood much worse reputation]]. Many memes compare the two, often making fun of the latter.[[/labelnote]]

** Not that Undertale the Musical. [[labelnote:Explanation]]Due to this Undertale the Musical sharing its name with [[https://youtube.com/watch?v=MobkO51msMI a different Undertale fanvideo]] also called Undertale the Musical, AKA Story of Undertale, which has a [[SoBadItsGood much worse reputation]], many memes compare the two, often making fun of the latter.[[/labelnote]]

*** MOTI's cover of [[https://www.youtube.com/watch?v=KYdKDGq_1Cw BIG SHOT]] somehow manages to be ''even more insane'' than the ''Music/JunoSongs'' version, giving Spamton two voice actors (Juno and Tom Previte) in one fast-paced, chaotic, ReferenceOverdosed song. Naturally, it fits Spamton perfectly.

* CrazyIsCool: MOTI's cover of [[https://www.youtube.com/watch?v=KYdKDGq_1Cw BIG SHOT]] somehow manages to be ''even more insane'' than the ''Music/JunoSongs'' version, giving Spamton two voice actors (Juno and Tom Previte) in one fast-paced, chaotic, ReferenceOverdosed song. Naturally, it fits Spamton perfectly.

* CrazyIsCool: MOTI's cover of [[https://www.youtube.com/watch?v=KYdKDGq_1Cw BIG SHOT]] somehow manages to be ''even more insane'' than the ''Music/JunoSongs'' version, giving Spamton two voice actors (Juno and Tom Previte) in one fast-paced, chaotic, ReferenceOverdosed song. Naturally, most wouldn't have Spamton any other way.

** The thumbnail for the Genocide Package's "Power of NEO" (the battle with Mettaton NEO) has the caption "4 left", as part of a countdown to the "Megalovania" lyric video. In the final battle of the [[spoiler:Weird Route]] of Chapter 2 of ''VideoGame/{{Deltarune}}'', [[spoiler:Spamton NEO [[note]]whose body is nearly identical to Mettaton NEO's and is in fact implied to have hijacked the abandoned design that alternate-universe Mettaton made for his NEO body[[/note]] says "I TOLD YOU [4 Left]"]].[[note]][[spoiler:Spamton has a similar role to Chara in the Weird Route, counting down the number of monsters the player needs to kill. It just so happened that the example he gave to Kris in-game happened to also be the thumbnail for the Mettaton NEO lyric video, which in turn was a reference to Chara's countdown.]][[/note]]

* HilariousInHindsight: ''Deltarune the (not) Musical'''s version of "Chaos King" has the line "Strike the earth, let darkness rise!". [[spoiler:The second chapter of ''Deltarune'' reveals that this is exactly how Dark Fountains are made]].