Awesome work creating such a polished game! The graphics were lovely, and the levels were generally well designed. The controls were easy to learn, but very tough to master, which is great!
It was a pain to be restarting the later levels each time you die. The first part was often super easy, and the later bits were brutal. The timing of things like platforms for the first half were rarely synced, so you had to wait before you could advance. It would be nice if the first parts of the level were in sync, so you could quickly move towards the later part of the levels.
Great work for a demo, I really enjoyed playing it!