A brave as cute defender of the empire. I think too you should luffing the walk animation. It would be more dynamic.

 myabe making the upper part of his body go up and down one pixel could help the animation being less static. Nice for being the first work! x3

His legs look like they're flailing in the air, he needs to be taking a step (ie: lift, swing, land). Even though it mostly looks like his foot is the only thing sticking out, this: www.idleworm.com/how/anm/02w/walk1.shtml is often used to get walking animation. Try focusing on the foot position, shape, and angle, as well as body movement. The walking tutorial is very exagerated, so try to limit some of the movement.