Bad Time Simulator May 2026

The is one of the most famous community-made recreations in the Undertale fandom, specifically designed to simulate the notoriously difficult final boss fight against Sans . Originally released in 2016, this web-based application allows players to practice the intense combat mechanics of the "Genocide Route" without having to play through the entire game. What is the Bad Time Simulator?

The simulator mirrors the unique "bullet hell" platformer style of the original game: bad time simulator

Unlike other fights, Sans's attacks don't grant invincibility frames; instead, they apply a "poison" effect called KARMA that slowly drains your health over time. Accuracy and Differences Reddit·r/Undertale The is one of the most famous community-made

Sans often turns your heart blue, introducing gravity and requiring you to jump over obstacles. The simulator mirrors the unique "bullet hell" platformer

Players control a small heart (the SOUL) within a bullet board.

Created by developer , the Bad Time Simulator (Sans Fight) is a browser-based faithful recreation of the Sans battle. In the original Undertale , fighting Sans is a grueling experience that requires players to murder every monster in the Underground. The simulator removes this barrier, providing instant access to the fight for those who want to test their reflexes or practice specific patterns. Core Gameplay Mechanics

You must dodge rapid-fire bone patterns and "Gaster Blasters"—large skull-like devices that fire massive laser beams.