Here's a comment: Don't use 256 colors for a tiny image! Pixelart is about control, precision and efficiency for both pixels and colors. The less colors you use (for a given outcome) - the more impressive it is. The image is nice, but it really shouldn't require more than 20-30 colors for the same result.
I did this face in paint,but i adjust some erros of shadow in photoshop,but i have the paint version here,after i'll edit ^^.