while I know this is just a sketch I have the urge to critique |D
This is pretty good and I love the shading.
However, the head size looks too small in proportion with the facial features. The chin is too sharp. If it was even smoothed just a little bit it would look a bit more realistic.
The clock does look cool but it looks too far to the left on the face.
This is when you gotta draw the line between anime and realism. In anime it's normal for eyes to be big, but in realism the eyes are much smaller |D. Now you did a good job on the shape of the eye [much better then me] it would look better if you sized it down a bit.
Those nose looks a bit big to me but then again it could just be me |D
I'm not too crazy about the hair but then again I was never a fan of lighting the hair each strand individually