The light source seems pretty inconsistent. I think it would be helpful for you to pick a specific spot, probably upper right corner would work best here, and then shade according to that.
Additionally, the AA on the outside seems a little pointless here. It just makes it look a bit messy, especially since it's so much darker.
For the anatomy, consider putting the shoulder a bit further back from the head? Or having the mouth be a bit further out.
I really like the front hands, though. I love how you've really got the gorilla knuckle-stance down. A little more contrast might be good if it's meant to be seen at 1x, but it looks fantastic at 2x zoom.