Deltarune is an episodic role-playing video game created by American indie developer Toby Fox. Set in a parallel universe to his 2015 game Undertale, it follows Kris, a human teenager predetermined to save the world alongside Susie, a monster, and Ralsei, a prince from the Dark World. Throughout the story, the party establishes relationships with a variety of allies and opponents. The combat system is turn-based and uses bullet hell mechanics. Like in Undertale, enemy encounters can be resolved peacefully or through violence. The game shares several characters and gameplay elements with Undertale, but takes place in a separate setting and features an overhauled battle system with multiple party members.