Undertale is a role-playing video game created by indie developer Toby Fox. In the game, players control a human child who has fallen into the Underground, a large, secluded region underneath the surface of the Earth, separated by a magic barrier. The player meets various monsters during a quest to return to the surface, mainly through the combat system; the player navigates through mini-bullet hell attacks by the opponent cyclically, and can opt to spare monsters instead of attacking and killing them. These choices affect the game, with the dialogue, characters, and story changing based on outcomes.