The lighting problem is mostly sorted now and seems fairly consistent.

I decided to add a different ball to the animation to experiment with working with the visible weight of objects. I feel it went well, but due to the fact it isn't as elastic as the animation is over fairly quickly for it. I had it roll down a hole (its own shadow) to shorten the time creating it (so I didn't have to draw it into every following frame as it is just a test piece).



Also for one version I tried colouring in the balls to see how that would look.