So...is it sliding along the ground? It never actually picks its feet up, so I'm confused. If it's supposed to be walking, give its legs joints and bend them so that the poor guy can walk. Also, since the side walk seems to be straight from the side (correct me if I'm wrong), we should be able to see its left legs, but they're invisible. Also, in the front view, the walk cycle should be front-left & back-right legs together, then front-right & back-left legs together (same in side view, for that matter). The way you have it now is not how four-legged animals walk ever at all. It's a good start, but it needs work to be a real walk cycle.