Hate to say, but I agree with the other guys. The upgrade system is waaay too slow for it to be of any benefit or use. Not only that, but the game itself just feels bland and gets boring too quickly. Buzz is right, there's plenty of other games that have done this and are miles better. Pixel Purge being one that comes to mind immediately. Sorry, but this just isn't doing it for me. A nice try, though.