The timer is too stressful, it doesn't make the game relaxing. You need an insane amount of luck in the higher levels for the starting cards. Too random. The continous rewards is useless in high levels because of the amount of cards and randomness would make the player lose all 5 hearts inatantly. There's also no other way to get coins. By the time the player reaches the high levels, they would have no more coins. I suggest to add daily coins. Atleast a daily amount of 10-15 coins would do.