Short, easy, fun, I actually like how each area is a different texture, but I'd recommend making it more obvious which surfaces are shootable and which aren't. Jumps are all pretty standard, 9 and 10 are much harder in comparison to the rest IMO, and I'd consider making the tele doors at the end of each jump bigger, or just make a strip at the end which tele's you, since I never find it fun waddling to the doors to get to the next level.