Played a lot to "Palm island", a solo ressources gestion card game which you play in the palm of your hand (No table needed, you can play it standing in the subway)
You can play either the first or second card of the deck. And when you play a card you put it behind the deck after tapping (90°), flipping (face down) or reversing (180°) it.
I want to take the same direction. Since the material I thinking with is a classic card game, the "reversing" part is not usable. But flipping and tapping are mechanicals ideas to think about.