Yo, this was great. I thought it was going to be a "99 Bricks" clone, but the cards were a great layer of choice. Amazing idea.
My only suggestion would be to consider just giving the player a hand of 3 or 4 and having them draw back up to their maximum hand size each time they play a card. That way you always have options. That's essentially what I did in my game and I found it worked really well (better than expected actually).