I think making the goal so rigid is the biggest flaw.
Also, with just pixels the game doesn't seem to be fun enough, but I do see big potential. I'm gonna add it to my mechanics folder actually.
Like, I enjoy just going through mtg cards online, reading them, and trying to find some good ones. It'll be cool if instead of trying to find a cool unit I would have the ability to merge some cards, mutate some properties, and make myself some powerful stuff.