For those that need help, GraphicDesignC made a walkthrough at this link here (didn't post the actual walkthrough due to spoilers) http://www.kongregate.com/forums/3/topics/100342
This game was very hard after level 5 or so. It demanded you to get the powerup cards or you'll die quicker than you could blink. Very well made, boss designs are interesting and the gameplay is superb.