First half is fantastic. xuser's part is probably my favorite- it feels like a fusion of ValentInsanity and ML500's style and I love it so much. The level tapers a good bit near the end tho.

Really good for a megacollab, although I definitely think the concept of only using the "default" colors in the editor, while really creative, would be executed a lot better in a solo project where there's more visual consistency.