I love the characters, Turbo. Really amazing stuff. I think I agree with Esker, though, in that they should be pulled down a few pixels and more... perspectivately centralated.
I'd also consider taking out the dithering on the floor (at the bottom of the wall). Dunno why, but it might have something to do with the fact that I don't read it as... anything, really. Like, I read it as shadow, obviously, but the light is directly over head on a flat wall, so there'd be nothing to cast shadows. A nice crisp transition from floor to wall would play better in my mind.
Like I said though, ace work. Love it.