Supertuxkart

Tremulous - The game was so fun back then (like 10 years ago ?) I guess it's a dead game now.

InfraArcana was a little bit tough but is a very good roguelike

Not quite what you are asking for, but here's a list of source ports of commercial games, most of which have Linux ports.

Oh and I'll single out The Ur-Quan Masters as an older source port of Star Control II. Old enough that the port itself is nostalgic for me, although it's still being updated by the looks of it.

For me it's CDDA, a quite realistic and deep apocalyptic survival game with very frequent updates(on the experimental branch)

I am a big fan of Neverball

I did a little review of my favorite source ports here: https://beehaw.org/post/477938

Arguable if you can call it a game or not, but there is Overte. It is an open-source social VR platform. (without crypto so please no pitchforks)

As one of its developers I might be biased, but I wouldn't be one of the developers if I didn't honestly believe in the project.

Minetest!

I used to play openarena (Q3a ish) a lot. And we had some group games of freeciv. I never got torcs to work well enough to play. That would have been great and simulation would be the perfect kind of "game" to free / open source. And countless hours of nethack on every platform I had (which was a few). Other roguelikes too. Ones that actually are like rogue, that is. Even rogue.

But all that was a long ago. Should maybe explore more.

Thanks for the Veloren recommendation, I liked Cube World, it just didn't work out well.

Pokemon Auto Chess. Literally what the name implies, a Pokemon auto battler game. Honestly it's really well-polished for something only a couple of people are working on (aside from commissioned sprite artists) and has an active community to go with it.

[](Dungeon Crawl Stone Soup)

classicube is pretty cool, open source Minecraft classic-like game (so, no crafting or survival aspects, limited world sizes)