Well put together, as always.
Graphics are nice, controls are smooth, sound effects are synced.
One thing I question though is the bosses. I understand your idea of using different types of bullet patterns for the bosses attacks, but I feel some of (if not all) of the non-targeting patterns have safespots between the bullets, and then the pattern lasts long enough to easily put a heavy dent in the opponent without taking hits.
But anyhow what I am trying to get to is that I think the bosses' attack patterns should have shorter durations to increase the challenge. Or, for that matter, add different difficulty options.
Well done,
KarpOfMagik