You got a good game going here, the art is simplistic but cute, and the gameplay seems balanced. As the others have said though, the game is really difficult to understand at first. To mitigate it, I recommend investing more time through the tutorial, explain more in-depth what exactly will happen. Think of it like you're teaching someone new to a card game everything about the rules, rather than just giving the steps, you explain what happens when you perform the actions.
Overall, again, good game. All it needs is that extra bit of polishing in the tutorial, and I think it'd be much more enjoyable.