If you’re a fan of Undertale, you’ve probably faced Sans and know how challenging his boss fight can be. Bad Time Simulator brings that experience to your browser, letting you practice dodging attacks, improve your timing, and explore different fan-made battles.
At Bad Time Simulator, you can play over 150 free browser games inspired by Undertale, Deltarune, and their alternate universes. The collection includes Sans Fight Simulator games, AU boss battles, and fan-made challenges featuring familiar characters.
There’s no download or installation required. Just choose a game, start playing, and see how long you can survive. New games are regularly added to the collection.
Explore the games and try your next boss battle at Bad Time Simulator.