Finished the game, at the start it was a bit confusing which key to press to change color (maybe it should be mentioned somewhere that key down will change your color - even when you're mid-air?)
Really liked the double jump puzzle, where you had to time when to change to colors (and get colors in the correct order), clever!
Also one more bug, R key seems to not work sometimes, but that may also be due to me playing on browser.