A 2015 indie RPG where you can befriend or fight monsters in the Underground, with choices affecting narrative routes (Pacifist, Neutral, Genocide) and self-aware meta elements.
- Developer: Toby Fox
- Genre: Indie RPG
- Platforms: PC (2015); later PS4/Vita, Switch, Xbox
- Mechanics: Bullet-hell style combat dodging, ACT and MERCY systems to resolve encounters nonviolently, multiple branching routes, save/meta subversion
- Notable: Memorable soundtrack, subversive storytelling and humor, strong fan community and cultural impact