The lighting:From the preview, lighting seems to have changed. But I have to say I'm not a huge fan of the current preview, as some others said, they look like plastic if not dead. But it's a work in progress so it might be better later on.
While light was obviously used to render it initially. The lighting from what I remember is messed with in the 2D renpy engine when the images are put together. This is done to try and account for day time change. But because the shadows are built into the 2D image it makes it look messed up.
If he wanted to do this right he should have rendered to a 2D contour/height image. In short it shows the height of the body in relation to surrounding body. Then he could have looked at the slope and used it to mimic light and shadow change across the day.
Just think of it light a terrain map use for a human body images.