Excellent game! The gameplay was really interesting and I liked how much mileage you got from the simple concept. The graphical effects are really nice too, it's a very charming game.
For next time, I would say to put more work into the controls, maybe let us press right shift to change colours as well as left shift, and to work on the level design to make it a bit more lenient. For example, move the platforms a bit further apart so the player has more time to press jump and then shift in quick succession, as I was struggling to pull that off.