I completely agree - 99% of the time, I play (and test) the game on Firefox. It looks like it runs there even better than on Chromium. I've tried to tell the main developer that it 100% works, but the badge is still there; you can ignore it.

What device are you on? I have an issue which only happens on Firefox on Mac where WebRender is disabled by default, causing massive drops in FPS. I think it works fine on Windows though.

A laptop with Intel Core i5-6200U (Linux, X11).

This game is made by Tobias Springer, author of YORG.io and YORG.io 3 (and other contributors).