# Undertale Yellow

Undertale Yellow is a 2D role-playing video game released on Game Jolt for Microsoft Windows on December 9, 2023. Developed by Team Undertale Yellow as a fan-made prequel to Undertale, the game follows a human child named Clover, who possesses the yellow soul from Undertale, as they journey on an unfamiliar path to the surface after entering the monster-inhabited Underground. The game received generally positive reviews upon release.

## Gameplay

Undertale Yellow is a role-playing game that employs similar gameplay mechanics to Undertale. The player controls a human child and explores the Underground, a vast subterranean landscape where they must battle monsters and solve puzzles to progress. Alongside familiar locations and characters from its predecessor, the game introduces many original areas and monsters. In combat, players are given the choice to defeat monsters through violence or pacifism. Choices made by the player both inside and outside of combat determine the game's story progression, tone, and difficulty, with Undertale Yellow employing a comparable theme of morality to Undertale.
During battles with monsters, the player controls a heart representing the human's soul to evade bullet hell attacks from their opponents. Unlike in Undertale, the soul's color remains unchanged as the game progresses. However, some boss battles introduce gimmicks that alter the soul's movement, abilities, and appearance in various ways. On their turn, players can choose from the options FIGHT, ACT, ITEM, and MERCY. Selecting FIGHT causes one or more shooting targets to appear instead of the elliptical pattern from Undertale, but damage is still dealt by timing button presses. Otherwise, the game's battle system is nearly identical to its predecessor's. Defeating enemies by any means will reward the player with gold, but killing them will also earn the player EXP, which can increase their LOVE. However, opting to kill enemies instead of sparing them will permanently influence the player's story route and ending.
Undertale Yellow includes several quality-of-life improvements over Undertale, including some which were added in Undertale's spiritual successor Deltarune, such as the ability to run in the Overworld for faster travel. The game also allows the player to retry boss battles immediately from the game over screen, a feature not present in its predecessor. In the game's configuration settings, players can also access various accessibility options, including the ability to make running automatic and an "easy mode" that boosts the player's defense to reduce the game's difficulty.

## Plot

Undertale Yellow is set in the world of Undertale, where monsters were sealed beneath Mount Ebott with a magic spell following their defeat in a war against humans. Many years later, Asgore, the king of the monsters, has collected five of the seven human souls needed to break the barrier to the surface world. The story follows Clover, a human child with a soul embodying the trait of "justice," as they enter the Underground to investigate the disappearance of the five humans. Falling through a crack in the Ruins, they meet Flowey, a sentient flower, who teaches the player about the game's mechanics. Flowey accompanies Clover on a journey to Asgore's castle, where Clover can cross the barrier to return to the surface.
While traversing the Underground, Clover explores many new locations, including previously unseen sections of areas from Undertale. They encounter numerous monsters, such as Dalv, a recluse living in the Dark Ruins; Martlet, a member of the royal guard stationed in Snowdin Forest; Starlo, the sheriff of the Wild East; Ceroba, Starlo's childhood friend and the wife of a deceased scientist, Chujin; and Axis, a hostile robot residing in the Steamworks. Most monsters engage Clover in combat, giving them the choice to either fight and possibly kill them or show them mercy.
The game's story diverges based on how the player chooses to resolve battles with monsters. If the player chooses to kill some but not all of the monsters, they experience the "Neutral" ending: when Clover almost reaches Asgore's castle, Martlet offers to keep them safe in the Underground instead. However, Flowey kills her after Clover agrees. Enraged, he admits to manipulating Clover's journey to ensure they reach Asgore alive, in order to steal and absorb the human souls while Asgore is distracted. With his plan failed, he attempts to absorb Clover's soul during a nightmarish battle in his mind. However, Flowey eventually grows bored of the fight, citing Clover's refusal to surrender. Disappointed with this outcome, he decides to reset the timeline to achieve a better ending in the next run, abruptly restarting the game.
If the player chooses to spare all of the monsters, they experience the "Pacifist" ending: Ceroba discloses that her daughter Kanako has "fallen down" (a fatal condition rendering her comatose). She accompanies Clover through the Steamworks as a shortcut to the royal lab to investigate Kanako's situation. The two of them are interrupted by Starlo, who questions Ceroba's motives and chases her away. It is revealed that Chujin attempted to create a soul-strengthening serum using the souls of a human and a "boss monster," which Ceroba intended to perfect using Kanako's and Clover's souls. Martlet, Starlo, and Clover confront Ceroba, but she is able to overpower all of them. During the final battle against Ceroba, Clover learns that Kanako fell down after requesting that her mother test the serum on her. Ceroba obliged, but the reaction caused Kanako to fall down. Upon being defeated, Ceroba collapses in anguish and asks Clover to finish her off.
If the player kills Ceroba, Starlo will express hatred towards Clover and leaves with Ceroba's mask. Martlet escorts Clover to the castle's throne room, and the game ends with Asgore reluctantly claiming their soul in battle. If Ceroba is spared, the player experiences the "True Pacifist" ending, where she expresses remorse for her actions before reconciling with the others. After reflecting on their journey, Clover decides to sacrifice their soul to aid in the freedom of monsters. During the game's credits, Dalv, Martlet, Starlo, and Ceroba float Clover's hat and gun down a raft leading to Waterfall's garbage dump. Later, Clover's soul hears and answers a call for help from "someone."
If the player kills enough monsters to exhaust the kill counter for every required room of the game, they experience the "No Mercy" or "Genocide" ending. The game's tone changes significantly during this route, with the soundtrack becoming more ominous, monsters disappearing from the Overworld, and most major fights becoming more intense and difficult. Additionally, Clover exhibits increasingly aggressive and threatening behaviors as the story progresses. In the Wild East, Clover kills Starlo in a duel, followed by a vengeful Ceroba. Before they reach Asgore's castle, Martlet tries to stop them by transforming into a powerful being with a serum from the royal lab, but is defeated and killed. After the battle, Flowey accidentally reveals his desire to steal the human souls and gets shot to death by Clover. The game ends with Clover killing Asgore, freeing the human souls and escaping the barrier.

## Development and release

   Undertale has inspired many to create amazing things and it is no different here. After playing through Undertale for the first time I was lying in my bed when the idea almost randomly popped into my head. The pieces seemed to line up perfectly so I got to work as soon as I could.
Development on Undertale Yellow began after Toby Fox, the creator of Undertale, approved it upon contact from Team Undertale Yellow. It would continue for nearly seven years. Created with the GameMaker Studio engine, the game was conceived by writer and composer MasterSwordRemix. Its official announcement came in April 2016, accompanied by a trailer with an unspecified release date of "soonish." Over the course of development, several animators, artists, composers, and writers joined Team Undertale Yellow, ultimately forming a team of over twenty people. Although a winter 2022 release was originally planned, the game was eventually released for free on December 9, 2023.
The Undertale Yellow Soundtrack consists of 135 tracks, mostly original compositions, though it also includes several tracks based on those from Undertale, sparking a debate over the game's usage of copyrighted material. Sebastian Wolff, the CEO of Materia Collective, which licenses the music of Undertale, criticized Team Undertale Yellow's approach to publishing their game's soundtrack. In a series of public Twitter posts, Wolff decried the team's use of Undertale musical motifs and requested to see the "defined permission that Toby granted 7 years ago" that would have allowed Team Undertale Yellow to use and remix Undertale's music. Wolff additionally made the promise that if Team Undertale Yellow was able to prove him wrong, he would donate $10,000 to them. In response, Fox stated that he had not given recent permission but criticized Wolff's handling of the situation as "extremely unprofessional." As an apology, he offered to donate $20,000 to Team Undertale Yellow's charity of choice, AbleGamers.

## Reception

Undertale Yellow was highly anticipated by YouTubers and received generally positive reviews upon its release, garnering around 350,000 downloads in its first month. Before its release, Dominic Tarason of Rock Paper Shotgun declared Undertale Yellow to be his "favourite unfinished fan-game". Will Nelson of PCGamesN recommended it to Undertale fans, noting how Toby Fox started out with a fan game of EarthBound and expressing that "seeing another group of developers bring it full circle [...] is nothing short of astounding." Aleks Franiczek of RPGFan also praised the game, stating that "in some respects, [it] even surpasses [Undertale]".