Undertale

Years after a devastating war between humans and monsters, a child has fallen through a hole and into the monsters' underground world. Under the care of a kindly monster woman named Toriel, they learn the basics of the underground world, including that they may be attacked by other monsters who are less friendly. After the child leaves Toriel's care, it's up to them how they proceed through the underground, including whether they kill the monsters in their way or try to find peaceful resolutions to conflict.

Players can choose to attack monsters directly or perform friendly actions in battle, such as showing mercy to opponents. This allows players to resolve conflicts without bloodshed, but some monsters are more difficult to do this with than others. The player may need to perform certain actions in the overworld before some monsters can be befriended.

The game remembers certain player actions across playthroughs, mainly in reference to how violent or peaceful they were. Resetting to an earlier save or starting a new game after specific actions are taken can affect how NPCs treat the player and how the story is ultimately resolved.