Running Doom on KaiOS
Solution 1:
https://github.com/pelya/doom-kaios/releases
You will need to provide your own DOOM2.WAD, then import it into the app (open KaiOS file manager, click Options -> Share -> Freedoom). You can copy DOOM2.WAD from your old Doom 2 CD, or buy Doom 2 on gog.com .
There's no netplay, because netplay is complicated for various reasons, but it might be added in the future.
And there's no music, because OPL3 emulation is very CPU intensive and slows the game to a halt.