I love Endless Sky, it’s honestly one of my favorite games! I have a pack of cool SciFi art that I found on Nexus and I’ve been slowly replacing the stock photos for my personal game. I’m also a sucker for TeeWorlds, it is delightfully infuriating and hillarious to play. I know that’s baby’s first FOSS games but I’m new to open source games. That’s why I want to hear your recommendations and see what are some other good ones out there.
Shattered Pixel Dungeon is currently the one that has me gripped most.
Apart from that it’s probably those derived from id engines. Last one I played was Jedi Outcast.