Really good game, brackeys made a similar one, but I liked the execution of yours better. My only complaint is on the moving platform level, where the platform takes too long to come back if you die (perhaps do a level reset when you die so the timing of the platform fits the respawn time?). Also I'd suggest making the first levels easier as a tutorial, that way the player can get to know the game before it really starts.
PS: I know my review focused more on the parts I find negative rather than focusing on the positive ones, but the game is really good and I enjoyed playing it.