Yeah, actually the more I look at the face you did, i'm starting to think everything's out of line a little bit as far as the face goes. I tried to show proportions in a psd, but I don't have a tablet at the moment and I suck with a mouse, so I'll just try to explain.
Draw a line straight down from the center of each eye, this is how wide the person's mouth should be.
Draw a line straight down from the tear duct of each eye, this is where the outside of each nostril should be.
As far as length goes, each person's features differ from anothers, so I tend to mess around with it a little bit.
If any of that made any sense, then cool, if not, then try looking at some photos or be narcissistic for a couple minutes ^_^
hope it helps and hope it's something you didn't already know.
and yes, I do love it. I agree with Konstruct, too. Another lightsource would be great and it would give you the chance to move those blues around so they're not all just in one spot.