Juicy! I really enjoyed the tactile feeling of this game; each action gave such rich feedback. It took me some time to realize that the combinations are counted on BOTH sides of the cards, and when I did, it blew my mind. Very cool concept and masterful execution!
My only negative is that the balance felt a bit too loose for my liking. In 10+ levels, I never felt like I was losing or applying all my best to making the most efficient moves, since it wasn't required.