I didn't understand the balance concept here. I used the cards but i though the game hard. Only won one match.

I dunno how to play this, I was able to figure out how to use my cards, but not how to actually deal damage.

Nice to implement a card strategy game! I would have put a little effort in sound effects, that would have changed a lot the game feel for the better! 

interesting, i think some visual feedback for player actions could be in order

Card based strategy game is good. Adding some more graphics, sound and effects would complete this game.