I think you should sharpen the robot. Right now I'm having a hard time seeing all of the details of the robot and it's a bit tough to make out since its such a busy sig.
After you sharpen the robot, blur parts of the bg (small parts). Like behind the robot would be a couple good places. this will help separate him from the BG and it will also add more depth (deepness XD).

The lighting is pretty god and you made good use of c4d's. I would ike to see some funky robotic text in there though. Maybe a nice offwhite color with a techno font.

Cool coloring though, i like it.