Very good progression shown here. Shows that you don't draw the "final product" right away but have to work for it to look good. I think many beginners don't know that.

The walking cycle is also pretty good. We can clearly distinct the leg in front and the one in the back, and BOTH move forward, rather than both legs being on the same layer and the walking cycle looking as if only one leg moves forward.

Also, I like that you included Radiohead's "National Anthem". Made me dig out Kid A again, and I'm listening to it right now as I write this review. :D