First off, this is a really cool idea and it certainly fits the theme well.
Some feedback that I’d give is to make the ticking noise only when the player is on the map, or perhaps even shortly after making a move and it could ramp up with the fewer moves you have left. A bit of music could be playing during the card selection process.
Perhaps it was just me, but finding that little blue arrow in the bottom right to make the game full screen made the experience much better. It wasn’t obvious to me, but that could be my lack of knowledge on the unity engine.