Yeah, I heard that Joe Madureira did a lot of the art and designs for this.
He's a great illustrator, but he suffers from the same problem that a lot of great illustrators suffer from.
When he's drawing something else, applying his crazy style to someone elses idea (like Spider-man or the Incredible Hulk), then he's great!
BUT, when it comes time for him to do some design work of his own, it tends to suck. Yeah, he's good at making it look cool for a few single pictures, but just because something LOOKS cool doesn't necessarily make it a good design.
Mario doesn't necessarily look cool, and yet he's lasted ages. Heck, you could say that about almost every character that's actually been able to stand the test of time.
Eh, I had no interest in this game to begin with, and it sure was fun listening to Yahtzee tear it apart.