If you want an old classic, I've been playing rollercoaster tycoon 2 recently and there is an open source engine for it (openrct2) that has native linux compatibility. The controls take some getting used to, But I think that artstyle looks totally amazing.
Or even the first RCT as it's written in assembly. Can't get much more efficient than that, even a potato can run it.
I'm also amazed by it. How can you write a full game that looks as good as Rollercoaster Tycoon when you're shifting bits left and right on the stack? Some kind of wizardry, that's what.