I really like "dark, moody and atmospheric"...perfect for a young man who is just entering those interesting teen years.
I love this portrait!
Anyhow, I think that you have lost the unification of the light in his face...i.e., the left eyesocket is much too dark for an area that is surrounded by light.
Here is a crude (sorry) example of what I am talking about....in the picture on the right, I lightened your son's left eyesocket in Photoshop.
It is subtle, but I hope that you can see what I mean when you compare it to the unaltered pix on the left.
Shadows that are in the light are never as dark as a shadow in a dark area.