What another great work of art from you!
Everything about your last piece is also evident here. The simplicity of the background helps me to focus more on the robot and its purpose in this picture.
The lighter background contrasts very well with the darker robot, bringing the viewer's attention to the bot and not much else. I really like the addition of subtle color on the robot. Putting just a little bit of color adds a whole new view on any type of art. The orange on the weapon (which I assume is some sort of flamethrower) and on the robot's shoulder work well with each other.
I really like your drawing style and I hope to see even more from you in the future!
~ GC117