How loosely are you taking the term "Card Game?" (Not what I'm gonna make but feel free to be inspired) Could you make something like a dungeon crawler where you have cards that move you around instead of normal WASD or arrow key controls?
I think it should just have something to do with cards, im in my case using attacks as cards like you pick up a fireball card and then you shoot fireballs like that I dont want to spoiler too much
