Looking at the console I quickly get "No WebGPU support; not starting" (which is correct when I check the compatibility matrix, I'm on non-nightly firefox) but the page just keeps saying "Loading" forever. Even for a demo it would be nice to surface that error to the user so they know not to wait around waiting for some potentially giant game to load (which was my first assumption).

Edit: Tried again in Chrome, the game loaded after awhile, but no 3d geometry rendered. I had a HUD with crosshairs, scoreboard, ammo. The game said it started. I could see another players name moving around, and responding to my cursor movements as if I was supposed to be in a 3d environment. Clicking when my mouse was a bit below their name seemingly killed them (or maybe that was a coincidence). But this was all just on top of a black screen.

On a M1 mac if that helps at all.