Undertale

Undetale is an episodic role-playing video game Developed and Published by Capcom.Players control a child who has fallen into the Underground, a large, secluded region under 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, and can opt to pacify or subdue monsters in order to spare them instead of murdering them. These choices affect the game, with the dialogue, characters, and story changing based on outcomes.

Undertale is a spin-off of the previous game, Deltarune (for which Undetale is an anagram), but its setting is "not the world of Deltarune", according to Capcom, though characters and settings may bring some of Deltarune's world to mind.