Not Bad...
I actually came to your art expecting it to be rather crappy. This one has some promise, so already I have had my preconceived notions some what shattered.
I think you have done well so far with the texture of the metal, but a few of the other areas could use some work as well. It would have been nice to get some stronger highlighting and shadows over all. At the moment it seems like you tried to get some lighting in there, but didn't push it hard enough. So as a start it is good, now you need to push it over the edge.
As for the design. I think it is alright. The robot is simple but I think that with the color scheme, textures and poses, simple was the best way to go. Making this overly complicated would have made it seem like you were grasping at straws just trying to make it better
The background is a little odd and distracting. Perhaps a smaller pattern or a blurred one would have been the better choice as well.