That is a lot of spin :)
Liked the music loop, liked the spin liked the damage charge up but while I was taking damage there seems to be no game over state or win state which is a bit sad. The bosses seem to always shot at the current player position which makes it easy to avoid those, perhaps you could measure the angular velocity to estimate the required lead, that is what I am doing so you can not easily outspin the shoots.
Liked what I saw, its quite fun any future plans for this?