Well, I'm a little late getting to everyone's games. So, what I have to say has already been said....
Collisions are not forgiving to the player at all.
I couldn't make it past level 3. I can't imagine there being 6 levels harder than that one.
However, the controls and movement felt very polished. The visual effects were great!! I just wish I could've played more levels. Really good job on the game!