Pretty great, but there are a few things I would of change.
First of, I liked your use of the theme, but I would of gone a bit further and do something similar to Ikaruga (Shooting white bullets protects you from white attack, shooting black bullets protects you from black attack)
Second, I think the bosses had nice patterns but sometimes felt impossible to dodge with how fast they could go or their sizes.
Third, (and this is more of a personal preference) it felt weird to me that the player HP was to the right.
Otherwise, I think the music bugged when played since I could hear two boss theme at the same time. But never the less, you made a really interesting game.