I made a version of Quake 2 using GLES 1. It is based on Yamagi Quake 2 v5.34 with some substantial rewrites and simplifications.
You can find the files and the sources here:https://github.com/thenesis-org/lp-public/releases/tag/v1.0
Initially I made this port to test my software rasterizer on PC and some embedded platforms but finally I tried to make a clean release.
I put my efforts into making the sources as clean and portable as possible but I don't have the time to rework everything. So the graphic parts received most of my energy.
It works pretty well with all official mission packs and has a decent framerate. The low framerate at some places is mainly due to the GLES 1 implementation which spends a lot of time doing useless things according to apitrace. But there is also a lot of possible improvements on my side.
Multiplayer works well too and you can play GCW Zero vs Raspberry Pi vs PC if you want.