It had to happen: in-chat multi-player #Quake III Arena #webxdc app, running over @n0iroh and using the fine work of https://ioquake3.org/ folks. Quake3 app is 1.2MB but you need to download once a game file of ~50 MB. It's only one level.

Realtime-P2P-networked multiplayer gaming arranged through securely end-to-end encrypted email, from a group chat!

Both Quake3's in-game chat as well as game play messages have forward-secrecy. What a weird future, eh? :)

https://webxdc.org/apps/#wofwca-quake3