History VideoGame / UndertaleYellow

** The Pacifist route final boss, [[spoiler:Ceroba, is overtly Japanese in aesthetic in an otherwise SpaghettiWestern inspired game, and (like the other final bosses) utilizes the ShootEmUp mechanics characteristic of the Yellow Soul, which might bring to mind the BulletHell genre codifier itself, VideoGame/{{Touhou}}. The battle theme that accompanies her second phase is also very reminiscent of Creator/{{ZUN}}'s musical style.]]

** The detention room that Axis tosses you in the Steamworks has a suspiciously familiar table that features [[Franchise/FiveNightsAtFreddys a computer, a table fan, and a phone]], and interacting with the computer will prompt a quote about how nice it would be to have security cameras that monitor monsters in the Steamworks, but that they don't exist. You even escape it through the vents, not unlike how the animatronics can attack the player in ''VideoGame/FiveNightsAtFreddys2''. [[spoiler:Unsettlingly enough, the room even has a jumpscare (itself featuring none other than the "Purple Guy" ICE-E's P"e"zza mascot from ''VideoGame/{{Deltarune}}'') that shows up on the allegedly nonexistent security cam if the game has FUN value of 16-19]]

** The Telly-Vis monster has an attack referencing the iconic "Bouncing [[UsefulNotes/{{DVD}} DVD]] Logo" screensaver.

** Unlike ''Undertale'', ''Undertale Yellow'' let's the player do the pacifist path from the get go, meaning the player will not have to do a neutral route first.
** Also unlike ''Undertale'', doing a Genocide route doesn't taint future neutral and/or pacifist runs.

** In the Genocide route, after the boss battle against [[spoiler:Martlet, who gave herself extra power with the determination serum]], the area where you fought is shown to have been damaged by all the attacks that were used].

* AbnormalAmmo: Instead of changing weapons like Frisk, Clover keeps their gun and simply changes the ammo. Depending on the ammo equipped, Clover can receive different buffs for landing a critical hit such as increased speed for 1 turn when using the coffee ammo.

** The Neutral route final boss, [[spoiler:Flowery Encore, uses different animation styles in various stages you have to complete to "beat" him. In the one that looks like claymation that would fit right in VideoGame/Hylics/{{Hylics 2}}, Flowely drops eyeballs as one of his attacks. Said eyeballs look very similar to the infamous [[https://knowyourmeme.com/memes/prunsel Prunsel]] meme.]]

* MultipleHeadCase: Telly-Vis is actually two beings in a robot resembling a television who don't seem to get along; Telly is the screen, while Vis is the video player.

* HeelFaceTurn: Like ''Undertale'', you can do this: do something bad, then reset and not do the bad thing in the first place.

* RewatchBonus: On the pacifist route, when you're going through the abandon lab with Ceroba, she is rather insistent that Clover continue on their path, keeping them from checking their mail under the reasoning that the royal guards are looking for them at the moment. [[spoiler:Once you know that Ceroba was planning on ''killing'' Clover for their SOUL, it becomes apparent it's less about the royal guard finding them and more her trying to keep Clover from getting any outside hints that something may be up.]]

*** [[spoiler:If Clover kills Ceroba, Martlet decides to take Clover to see Asgore to try to talk things out. However, when it becomes Clover and Asgore intend on fighting no matter what, a heartbroken Martlet leaves, and a HopelessBossFight ensures where Asgore ultimately kills Clover, taking their SOUL. As Toby Fox's WordOfGod confirms that Asgore killed all six humans before Frisk arrived, this is the closest to a canon ending]].

* MythologyGag: There's a frequent joke throughout ''VideoGame/{{Deltarune}}'' of Noelle having a childhood fear of the ICE-E's P"e"zza mascot. In this game, if the player has a FUN value of 16-19, the computer in Axis' detention room in the Steamworks will show a jumpscare of the ICE-E's "Purple Guy" mascot. Doubles as a combined ShoutOut to ''VideoGame/FiveNightsAtFreddys'', both in ''Deltarune'' and the context in which it appears in this game.

** The Telly-Vis monster has an attack referencing the iconic "Bouncing [[UsefulNotes/DVD DVD]] Logo" screensaver.

* DevelopersForesight: [[spoiler:In the Neutral final fight with Flowey, the replicated boss attacks will only correspond to which of the game's bosses you defeated through violence. Any that didn't go down in a violent fashion have their attack skipped.]]

** The detention room that Axis tosses you in the Steamworks has a suspiciously familiar table that features [[Franchise/FiveNightsAtFreddys a computer, a table fan, and a phone]], and interacting with the computer will prompt a quote about how nice it would be to have security cameras that monitor monsters in the Steamworks, but that they don't exist. You even escape it through the vents, not unlike how the animatronics can attack the player in ''VideoGame/FiveNightsAtFreddys2''. [[spoiler:Unsettlingly enough, the room even has a jumpscare that shows up on the allegedly nonexistent security cam if the game has FUN value of 16-19]]

** The first is an oddly non-lethal case; if Clover waits several minutes for Toriel where they fell in the Dark Ruins, she will actually return, hoisting a rope down for them to climb. Climbing up the rope will force the player back to the opening and title screen. [[spoiler:If the Neutral Ending is any indication, this could be due to Flowey resetting the timeline to prevent Clover from traveling with Toriel and dying]].

-->'''Flowey:''' "Ever heard of "don't bite the hand that feeds you"? But oh, "it's okay to bite Flowey because he doesn't have hands." Well, I ''used to!''"

** The second happens much later in [[spoiler: the Steamworks in a Neutral or Genocide route]], where Clover obtains a glass of Acid as part of a puzzle. The Acid works as a regular item, and if the player so desires, [[TooDumbToLive can make Clover drink it]], which ''immediately'' kills them. [[StunnedSilence Flowey is left utterly speechless]].

** Surprisingly, the ending to the Genocide route when compared to the ending of the Genocide route in ''Undertale'' proper. [[spoiler:Instead of Chara showing up and overpowering them to deal LaserGuidedKarma, Clover... simply takes the five [=SOULs=] with him to the surface after killing Asgore so they can be freed. Although the game puts you through the wringer for killing monsters that aren't a threat to you, Clover ultimately goes unpunished for it since Clover was ultimately there to save the [=SOULs=] and punish the monsters for killing them in the first place.]]

* EleventhHourSuperpower: [[spoiler:During the FinalBoss of each route, Clover's SOUL gains the shooting ability of the yellow SOUL from ''Undertale'', giving Clover a means of attacking during the enemy's turn. Doubles as AntiFrustrationFeatures as the player no longer has to decide between attacking or healing during their turn, which is a welcome change when all of the final bosses have very difficult patterns.]]