:D
Well, firstly I'd have to say that the lighting is more-or-less perfect and the shading is spot on. I also like the use of the smudge (?) tool to blend it all together quite well.
Personally, I don't see the head's odd shape to be a problem, at all. I think it significantly adds to the drawing's surreal side, which I think is very good.
My main recommendation would be to add more detail to the hands, feet and head. Otherwise, it's a great drawing.