Thanks for your feedback M. Lucanius and oCo. I will keep your points in mind for my next attempt. yes joints were very obviously kept this way to simplify things for myself as i wanted to understand what can work and what cannot.

Thanks again :)

To what M. Lucanius said, I might add that the black outline on the shaded side of the robot only does not work really well.

Another improvement axis: I see you made it very clear what parts of the robot can rotate and where: The joints are very obvious, I guess they could be integrated into the armor to smooth things out a bit and to simply make the robot more robust as a warrior.

Hope this helps.

Looks nice :)

I think you have a few stray pixels on the head (I use a darker theme) but other than that, my only suggestion would be to add a back leg to give him some depth.  The colors should not be the same as the front leg (closest to viewer), but should be of lower contrast and darker... I think (I am by no means an authority on this :P).

EDIT: here's a quick (and not so well done) edit illustrating what I mean.  I hope it helps :)

http://img265.imageshack.us/img265/6933/km1e.png

and another pose more true to the original

http://img688.imageshack.us/img688/6320/km1e2.png