Undertale is a 2D role-playing video game created by indie developer Toby Fox. Undertale has three main endings: Neutral, True Pacifist, and Genocide.

This TAS achieves the Genocide ending, which can be considered the "bad ending" to the game. In this ending, the player must complete the kill requirements in each area and then kill each area's boss.

The TAS is optimized for Z/Enter presses and then time, which means it aims to hit the Confirm key as little as possible.