I like the concept, anything space and wave defense is usually my cup of tea. I can't help but feel that the air you get to spin is way too little. As spinning around is the core of what you do. Having that tied to a (too) short stamina bar, which refills with a button outside of the shooting area. It becomes quickly difficult to rotate your guy to aim at the enemies.
I think adding a way to spin in both directions would make it feel a lot more responsive for the player.
Well done! :)