Boss Sim
A browser engine that recreates bullet-hell boss fights frame for frame.
What it is
A from-scratch engine that runs a boss fight in the browser. No framework, no build step for the game itself — a canvas, a game loop, and a pile of attack pattern definitions.
How it works
The fight is data, not code. Each attack is a JSON entry describing spawn timings, positions and movement, and the engine plays it back on a fixed timestep so the same fight runs identically every time.
What was hard
Getting the timings to match the source rather than approximating them by eye. That meant building a separate extraction tool first, before any of the fight itself could be considered accurate.
Use it
Hit Launch above. Arrow keys to move, Z to confirm.