Did you use a reference picture? The shading on the face is quite darn good if you did not(ie, you have the skill to do this yourself if you can get that decent a looking face!) I would say that as dark as the front of the shirt is, I would advise either lightening it up or darkening the face quite a bit more on one side to get it more consistent.

Front sleeve needs more work though unless my eye is seeing things wrong....Hard line blacks and partially transparent "inside" of the sleeve just looks rather odd. On second though... perhaps what I saw originally as a sleeve is something else... not quite sure what though.. For that matter, I would suggest making sure there are no hard lines in the shadows of the clothing to make it mesh better with the illustration as a whole...