Ah this is a great use of the theme, and a great use of BulletFury, well done! I don't really have much to say. The patterns were interesting, the bosses were cool, I adore audio synced things. Visually it's really clear what's going on, and every time I died it was because I made a mistake, not because the game was too hard. That's another point in your favor - it was really well balanced. It was difficult, but not impossibly so.
Honestly this is one of my favorite entries so far, absolutely a hidden gem!