Thanks for your really nice review about the game, much appreciated! I'm hoping to add achievements, a local 2 player mode, more stages and even more crazy background things.
You should really think about porting it over to the iPhone, the mechanics would really work well with the iPhone tilting.
After seeing how everyone was commenting on how the player takes damage I went ahead and took your suggestions and made the character blink when hit and temporary invincible. And yes, I did add some pixel blood