The Nurikabe is good. The pixel skill is there...and besides the hands and what's been said, I think it's some good pixel art.
The only thing that really concerns me, is that this new one sticks out from the previous three. It just seems to lack charm or something...and I think a reason is the angle--the current angle doesn't show any depth really...it doesn't even have to be drastic, just SOME depth will help it fit in with the others. Just a thought.
Other wise, I think the blandness might be in the feet--the original feet seemed to help capture a dynamic, flowing sense...I mean, even the way the body curved a bit helped it out some.
You probably wouldn't want to do such an overall after all the aa and other rendering you've done, but either way, it feels like it's out of place. I donno, it's just one guy's opinion...