Today I'm play the free (not open source) game Bottomless from itch.io https://picster.itch.io/bottomless (you can give money to the author though if you enjoy the game!)

On OpenBSD you need the package godot and run the game with godot --main-pack bottomless.x86_64 --video-driver GLES2 (it will give better performance with the GLES parameter).

It's a very nice game and I'd recommend it to everyone, it's fun, non violent yet challenging.