Just made a sprite sheet, I could use some constructive criticism.

I just made this edited sprite sheet of Mario, and sent it in for verifying, however, it was rejected because it "did not meet quality standards for the Custom / Edited section". I wasn't told how it didn't meet these standards, but I was pointed to this forum to ask for some constructive criticism, so that's what I'll do. I've uploaded the sheet as an attatchment, so feel free to check it out.
  Battledamaged Mario.png (Size: 46.49 KB / Downloads: 35)