Very creative idea! I like the music and how the entire game is on rhythm. It is very satisfying when I can blast a line of three enemies.
The tutorial is necessary to understand what's going on, I think.
I also wonder if it might be a bit more fun if the player could rotate sections more often, or even independently from the beat. The game would still be a challenge, especially when more and more enemies appear. And it would fix the frustration of accidentally rotating the wrong way.