I like this piece, but the shadow itself isn't natural (despite the fact that it's blue). When considering where to place a shadow, one should first consider its light source; the only way for this particular piece to be coherent would be for a giant hole to appear within the earth and have the sun shine through, which would in turn create a trigonometrical, proportionate shadow. Otherwise, however, the sun would create a shadow that would be much shorter (vertically) than the actual figure casting it (mainly on a level surface, that is).
I like how the colors provide for a sort of monotone, melancholy air, but at the same time I'd like to see some more detail in the picture (maybe some cans or parked cars). Since the shadow was really more of a technicality I'm basing my '.5' deduction on the lack of background detail (I hate drawing backgrounds, personally, but I still think they make a piece all the more interesting).