Pretty cool, but one flaw...
..the only thing I really really don't like about this is those blue plankton looking things that shoot out blue energy balls. Why can't they be destroyed?? They pump out 2-3 shots at one time individually towards the end; that's way too many shots for an enemy that can't be destroyed. Make 'em 10 shots to kill or something, they're just way too plentiful and deadly to not be able to be killed.
Anways, that was just my vent. Aside from that I thought the game kicked ass. Nice power ups and cool boss fight at the end, made it feel all worth it. Nice and fast faced, plenty of explosions and destfuction. Good job.