Very unique interpretation of the theme spin, gotta give you extra credits for that. The responsiveness of the controls has surprised me, they behave incredibly nicely, good job, and I love the jump higher if holding jump mechanic, that's always a good plus. The boss isn't very hard but I like that by the end it starts to become quite challenging, it isn't frustrating it lets the player get used to the mechanics and then it slowly but surely increases the challenge.
It's a shame it only has one boss, I was expecting more, but the one boss you have it's extremely good, very polished and well put together. Which means you went for quality over quantity, very nice.