My Simple Suggestion: use softer light and "fill" next time.
Reason: some of the features (shadow side of face and arm) appear "flat" and that leads to a "plastic doll" or "cut out" look. His right arm is an example. Appears as if the shadows there were "boosted" to get to a mid-tone level...and this may have caused the loss of tonal differences (and modeling of face/arm). But, other things can cause that too.
