Selaco is a first person shooter on the GZDoom engine. It's currently for sale on Steam and in early access.
The GPL source code is included with the game. I'm not interested in playing the game but I am curious about the source. Can someone upload/mirror it for me somewhere? It doesn't seem to be on GitHub yet.
(Obviously this is legal, it's the very point of the GPL - GZDoom is free to build upon but under the condition that those freedoms are retained)
You could buy the game on Steam, get the source code archive and then refund I guess. Or keep it anyway to play, I understand it's quite good.