Definitely one of the most challenging builds I've ever attempted. When I got to the hat, I topped out. I think I could probably make the hat if I kept at it, but I was content with calling it "good enough" for now.
Here is a reference image I used for the build:
http://lh3.ggpht.com/_UXXAcPLZCGk/TSYKoj0Sl_I/AAAAAAAAAZ0/7kGmZHVjx-k/s800/tetris%20mario.gif