avoid using dithering in such small sprites, because it tends to make things hard to read/look messy.

also... maybe its me, but the red of the eyes could be replaced with your most dark gray. as it appears to be invisible.

if the weird anatomy of the shoulders isn't intentional(and in the whole character in general)... you should fix it. you have enought room there to make more defined and credible shapes.

This better?

I dom't know how I forgot to add the mouth. :/