I do feel if you added more levels and maybe a larger viewport so you can see more of the levels when they rotate, this'd be an amazing game!

Good job!

That was an interesting experience. Towards the end, I had hoped that you pulled a "There is no game" hidden mechanic and bring out more of the experimental gameplay experience. 

The difficulty / complexity gradually increased with each level- that was done well.

You may want to reduce the level-rotation speed a little bit.

The choice of colours is decent- it was not too overwhelming or too dull but decently balanced, although you may want to reconsider the border colour and make it slighly less vivid. To me, it was more eye-grabbing than the ball.

UI- in the title screen, the text fades away if I wait and press nothing. You may want to keep the text from going away. Same goes for the controls instruction in the first level. Keep it until player gives some input. Besides that, I liked that you added the controls info in the first level rather than in the main menu/ title screen. It feels more context appropriate.

I can see this being a mobile game - you could set up a gyro control system instead of / along with arrows. 

It's a decent product for three hours of work and has good potential. Nice work!

Hehehe, worth the 3 hours of stress ;)