GNHUSTGames

Get ready for a bad time in Bad Time Simulator, a fan-made recreation of the infamous Sans boss fight from Undertale's genocide route. You control a small red heart trapped inside a black battle box, and your only job is to survive.

Sans throws everything he has at you — waves of flying bones, gravity-flipping gaster blasters, homing skulls, and blue attacks that only hurt you while moving. Use the arrow keys to weave through the chaos, holding still when bones turn blue and dashing between narrow gaps as the patterns speed up and stack on top of each other.

One hit usually means starting over, so every run is a test of pattern memorization and reflexes. With its glitchy Comic Sans text, iconic soundtrack, and relentless difficulty curve, Bad Time Simulator captures everything that made the original fight legendary — and just as punishing.