Super cute art and wonderful music. I had fun the whole way through, though I'd like to see how well the co-op thing works.
Collision on attacking felt a little wonky, especially for large enemies. I had to get really close to hit, but often ended up taking damage. The complete motion stop during the attack might have something to do with it.
Also I agree with the previous commenter that you have to be too close to the edge of the screen to move it. There were a number of times where I rolled right into a enemy I didn't know was there.
On the whole though, a super impressive entry!