Quake3Arena The Longest Yard in the Browser, open source, hand coded

Source Code here: https://github.com/rhulha/Instagib2

You can change the sounds, you can change the sensitivity using the console. Join the same room to play together.

Nice effort!

I got twice as much FPS on WASM port https://lrusso.github.io/Quake3/Quake3.htm though.