I don't think you're following the multicolour restrictions. I can see quite a lot of 8x8 blocks with more than 4 colours in them, especially around the teeth and the planet (less if you're using mid gray instead of light gray, i think)
I'm saying this now, because it looks like you're putting final touches on certain areas... Ofcourse, you don't have to follow the restrictions, but i think it would make ptoing a happier person if you did
I also had a hard time figuring out why the little guy was so terrified, but i guess that will become easier to understand if you work out the fly/bee on the nose
I like the self portrait, good stuff there