Bad Time Simulator

⚡ ActionVerified working · July 2026

About Bad Time Simulator

Bad Time Simulator recreates the infamous Sans boss fight from Undertale's genocide route — widely considered one of the hardest fights in any RPG — as a standalone browser practice tool. Dodge bone patterns and Gaster Blasters with your little heart in bullet-hell sequences that demand memorization and clean movement.

It's brutal, it's fair, and if you've ever wanted to actually beat Sans without replaying Undertale's whole genocide run, this is where you train.

How to Play Bad Time Simulator

Press Play and let the game load in your browser — it only takes a few seconds.
Play with keyboard and mouse. Most actions are exactly where your hands expect them.
Learn from each attempt — early failures are the tutorial.

Controls: Keyboard / Mouse

Tips for Bad Time Simulator

The opening pattern is scripted — memorize it cold; it's the fight's biggest damage check.
Move in small taps. Holding a direction drifts you into bones you saw coming.
Blue bones: don't move. Orange: keep moving. Drill it until it's spinal reflex.