I really like all the small aha moments in each level; it felt like there was also something new being introduced! The sprites and background music are also great!
The only small piece of feedback is that it would be nice to have some feedback (maybe a bzzt sound or an animation where it rotates and then bounces back) when you try to rotate incorrectly. I thought it was the game being unresponsive at first but then I realized I was just trying to rotate into an illegal state.
Other than that, it was a great game and I enjoyed playing through all the levels!