Undertale

Undertale is a 2015 role-playing video game created by American indie developer Toby Fox. The player controls a child who has fallen into the Underground: a large, secluded region under the surface of the Earth, separated by a magical barrier. The player meets various monsters during the journey back to the surface, some of which may engage in combat. The combat system involves the player navigating through mini–bullet hell attacks by the opponent. They can opt to appease monsters in order to spare them instead of killing them. These choices affect the game, with the dialogue, characters, and story changing based on outcomes.

Outside of artwork and character designs by Temmie Chang and other guest designers, Fox developed the entirety of the game by himself, including the script and music. The game took inspiration from several sources, including the Brandish, Mario & Luigi, and Mother role-playing game series, bullet hell shooter series Touhou Project, role-playing game Moon: Remix RPG Adventure, and British comedy show Mr. Bean. Undertale was originally meant to be two hours in length and was set to be released in mid-2014, but experienced delays.

Undertale was released for OS X and Windows in September 2015. It was ported to Linux in 2016, PlayStation 4 and PlayStation Vita in 2017, the Nintendo Switch in 2018, and Xbox One in 2021. The game was acclaimed for its thematic material, combat system, musical score, originality, story, dialogue, and characters, although reaction to the art style was mixed. It has sold at least five million copies. It was nominated for multiple accolades, including game of the year from several gaming publications and conventions, and is considered one of the greatest video games ever made. A game with a parallel story, Deltarune, released episodically from 2018 before its full 2025 launch; further chapters are in development.