the outlines read as very jittery, i think that going back over the lineart a little less conservatively with your darker shades would do it some good. For example, make the line where the helmet meets to body segement darker, since it's on the bottom of that segement, and where the arms meet the body, etc.
Also, i'd give a little more definition of the segments of the closer leg, the knee, shin, and foot segments all sort of blend into each other, making the foot look awkward in it's position. The legs of the robot (not just yours, but the reference as well) are rather curious. it seems like it'd waddle more than walk.
