@AlphaKiloPapa @SuperSnekFriend Depends on your preferred game genres. I play FPS games on PC mostly so I have several options in games and source ports as well as mods (Eduke32, GZDoom, Nblood, etc.)

I may look into OpenRA if I were to start playing RTS games. Recommendations in that department are welcomed.

There is a voxel game engine called Minetest that is much better for modded experiences than Minecraft.

Safe to say, we're not lacking options going open source and retro.