Don't take this as a flame, i'm just giving suggestions. I like the sprite, but i think there are some touches that could make it better is all......
Put some (just a wee teeny bit) of shading on the hair above the shine-line that runs across it. If there's some shade around that part of the head sa well it will add some shape to it, instead of just a flat head.
Also, it may be intentional to a degree considering the character, but there may be not enough shading on the skn...super-pale even on shaded areas.