While the low color palette you have used might be a good idea, the AA you applied doesnt work at all but makes the whole pic look jagged.
As for the eyes, you might want to actually pixel the shadows that they eye sockets, eye lids and eyebrow muscles cast, rather than just use dithering for so..
Aswell you could try balancing the goggles, since the bottom of the right part (from our view) could be moved a bit up.
