I loved your instrumentals and the models of the bosses very creative! I think there's a really nice concept here, but the boss kept interrupting me from trying to get into the flow of the music.
I'd love it if the bosses attacks lined up with your ability to respond more.
I wanted to try and follow along with the music, but if I waited until the bar had an open space available i'd get hit and stunned, but if I didn't I'd get a big red bar and am then unable to respond, or so at least it seemed to me.