The amount of detail is absolutely stunning. And overall a very striking complexion to how the body is designed. The head isn't to unique a design but still matches the body great.
I love is your subtle detail. such as the contrast of the dusty dirty smoke in the background to the sharp and faint steam incoming from his shoulders.
I would have like to see some more scrapes and tears on the robot itself. The image translates that he's been through quite some action. Having it fleshed out on his body texture more would have been great.
Hey, I just wanted you to know that I also have a robot with a face like that for one of my series, and I came up with it before I saw this, so I haven't copied anything. Just thought I should clear that up. Awesomee robot, dude.