Love the Shine and Metal rendering on the core of the mech. Very cool design. Good usage of color. I think the shape of his left arm becomes a little muddled though. I assume it's the same shape as the right arm, but it doesn't match up. Very small gripe, I know that mechs don't have to be symmetrical.
As a HardCORE scifi person I would have liked to have seen more mass in the mech's pelvic section, it just looks like the legs would snap off.
The design of the page as a whole is very cool, the clean lines and the slim font with the bonus images of other potential mechs to "choose" from make this whole piece look pretty much ready for print.