Mm... Good color choices and usage.
I think the eyelashes should be more defined, right now it looks more like face paint. But it does look nice as it is.
AA wise, you got it kinda wrong. One point AA should be the direct middle of the two colors, whereas you're just using one shade darker.
I gotta disagree with all of these points actually:
1 - The color choice is definitely dull - your values are decent, but the colors could be a LOT more interesting!
2 - Actually nevermind I don't disagree with this one
the eyebrow and lashes all suffer from this. More detail!
3 - One point AA should almost NEVER be the direct middle of the two colors, not even for values. This is just wrong
I'm working on an edit, I'll post it up in a bit...
[EDIT]
I didn't really do much with it, just tried to show some other ways of anti-aliasing along the eyelid there, and adding just a little color to your ramps
hope this helps! It isn't a bad start at all, it's just not taking full advantage of all the goodness pixel art offers...