Fun. Really dig the shadow. Since the shadow, and thus the background, are so important, the dirt and creases (not sure what the darker streak near the shadow or the lighter portions on the right really are) detract from the overall effect.
Looks to me like he's got an evil twin. I think you could have spread the contrast around a little better here. The black eye and white highlight in it show that you do have a full range here, but the rest of the subject is kind of clumped in the middle gray range. I'd increase the gamma, then punch up the blacks a lot and the whites a little.