The idea is good, but I think it needs more time. I didn’t fully understand the concept of "spin" in the game. I think it would improve with challenging elements that prevent you from attacking the boss. The audio design needs a lot of polishing.
There's not a big, central spinning thing or mechanic to it, but I tried to keep the concept of spinning in mind for most of the boss attacks and the movement of the player, as a design basis for this. That's why it's not so up-front maybe.
