A couple of nice projects I can think of are DragonRuby [1] - a 2d engine that uses SDL under the hood and mruby for its game logic. I created this [2] game jam entry in under two weeks of part time effort (has a few bugs but works)
[3] Sonic Pi - Music creation tool that uses ruby for instruction
I personally wouldn't but I have a leaning towards foss tools where possible, currently using godot, blender and gimp, my gamedev holy trinity.
Godot is good enough for a lot of 3d games especially if you have stylised art that doesn't need the highest fidelity rendering.
If I was trying to make a high production, high realism, commercial 3d game I would probably look at Unreal engine over Unity because I think the former is better but also Unity have shown they're willing test the limits of money extraction from their licensees, Unreal so far haven't pulled any similar nonsense as far as I'm aware.