I like the idea of creating a skill deck with the cards until you get some combination to beat the final boss, though I noticed that only one card takes effect and the other cards don't do anything. It seems like the last card chosen will be the one it uses, so even though I had 3 cards giving me health, the last card that had negative health was the only one that took affect, so I had 2 health instead of 6. However, this seemed inconsistent because sometimes I would get more than one effect, sometimes a card got duplicated and I had 4 cards with two of them taking effect.
I did beat the boss, but nothing seemed to happened. I also clipped through the buildings and got stuck a few times and couldn't get back out. On the second attempt, the game crashed.