Welcome to Pixelation Dnilb.
I actually like the hair. The skull is pretty close. The biggest issues are the eyes, nose and mouth.
The general relationship is that the tip of the nose will be halfway between the eyes and the chin.
The mouth is not nearly so wide, the creases of it will only ever extend to the pupils.
The eyes are more than twice as large as they should be. I've kept one eye to show the difference.
It's really the socket that takes up that whole area. The actual opening is quite small, yet the pupil gives the illusion of it being larger.
In human eyes, irises extend to the bottom lid and take up almost all of the space, not so much white shows.
The color you've started shading with is too cautious, it may as well be the same color. Try to get some contrast, make stronger statements with your colors.
The headband wouldn't cast a shadow on the forehead like that, as it's pressed against the head and is thin.
The shoulders need to be much larger, even wider than I have them.
Once the left eye is sized properly you'll see that the ear needs to come in more; as is it implies a very wide skull in this 3/4 view.
Something along these lines.