Hey, as I mentioned on the comment on the pikachu, I really like to see some Popart. I think it could be just a little better if you had chosen one primary color for each square and supported it with the colortriad or complemetary color. If you look at the Popart of Andy Warhol you´re beeing literally jumped on by a primary neoncolor.
good luck in the challenge, this is really good =D