This is the best I can do with it for now. Maybe I'll come back to it sometime.
Don't mean to be a pest. It looks like I stilted you some and you lost the freshness. So lets look at this one as an academic exercise as it stands now.
A couple things about shadows.
The cast shadow is in part darker than the part casting the shadow because there is bounced light coming back into that part. You have to look to see where and how that happens. That bounced light concept can be placed in such a way to separate the planes in the shadow.
And all the shadows on the same surface would have the same coloration to them. Looks like you used purple in some and black in others.
Sorry that I ground this one to a halt.
You're a game fellow. But I think your earlier version looked better.
Please listen to your inner voice. You have good instincts. Maybe the mind shouldn't take such a front seat.
Tis ok DA ... I knew it wasn't right somehow. Ok, I think I have a better handle on it now. Backing up a bit and moving it to the WIP gallery. Thanks as always for your input.