Deltarune is a role-playing video game created by American indie developer Toby Fox. The player controls a human, Kris, in a world where monsters live on the surface of the Earth. Kris and a classmate, Susie fall from Earth into a place called the “Dark World” where they meet Ralsei, who informs them that they are heroes destined to restore balance to the world. The players meet various beings who call themselves Darkners during a prophesied quest to seal the dark fountain. Mainly through the combat system, the player navigates through bullet hell attacks by enemies, which can be resolved peacefully or through violence. The first chapter of the game was released on October 31, 2018 for Microsoft Windows and OS X. The game's design resembles early 8-bit games like Metroid or Mario games. Deltarune is a spin-off of Fox's previous game, Undertale, but its setting is 'not the world of Undertale', according to Fox, though characters and settings may bring some of Undertale's world to mind. The game is speculated to take place in an alternate universe by many players.