Children of Morta is a couch co-op action RPG in a fantasy world of dungeon crawling. Enter the lives of the Bergson family where their land is becoming corrupted by darkness and evil. Slowly level up each character starting with the mother and father but later adding their children. Change characters between dungeon runs and learn each one of their intricate abilities. There is no permadeath, but survival is key to moving ahead and stopping hordes of evil.

https://www.gog.com/game/children_of_morta

Children of Morta comes with a native Linux edition and it runs very nicely. Performance isn't an issues since it is 2D pixel art. I was able to play with keyboard/mouse and an Xbox controller in co-op. The one frustrating thing about this game is... its very hard! We never finished the first dungeon. I love that the dungeons are procedurally generated... which is great, but until you finish the boss, you can't make it to the next level. There are several other areas on the world, but it was too hard to progress and we eventually gave up. We played about an hour a day for several weeks and couldn't make it past the initial dungeon. There is no "easy" setting either... good luck!

Specs:
Mint 20.2 64-bit
GeForce GTX 1060
Nvidia 470