You gave me permission to nitpick.
Anyways, the Nitpicks:
The lower legs' asymmetry looks pretty bad imo, the front of the upper arms could probably be covered better, and without a bright accent color he doesn't look too exciting, especially against that background. I also think the smoother texture of the system clashes with the limbs and bionicle pieces a bit.
The head is especially nice, but I really do advise adding an accent or brightening up the background. Funnily enough I had that problem once with metru blue and my old background.