Wow! This was tons of fun! I loved the movement of the game! It was very fluid! My only gripe was the 'black hole' thing that would pop up sometimes. I felt it inhibited my view of enemies for a second, which in a tight squeeze coule mean life or death. I would suggest maybe going for a more 'shockwave' type effect instead? That way you can still see everything going on but also get the effect across. Just my opinion though. :P
Great work! Tons of fun!!