I'm not sure how the scale fits into this. Is it because the shadows are bigger when the boject is closer to the light source? If thats the case I think the message would have been more direct with harder shadows (also on the web version there are no shadows at all). If that was the idea I think it's quite cool but I would have liked to see it more exploited, for example with levels with big objects that were too far away from the source and small objects that could cast a bigger shadow because of their positions.