I have puzzled over this for awhile and I just need some fresh perspective. Thoughts on the lighting especially would be much appreciated.
Here are two slightly different versions.
Very cool idea (the centaur cowboy). I like what you have so far, the problem I'm having with it, is your style. It seems somewhere between simple modeling of forms and very flat (low relief) cut paper style illustration. I think that is what's giving you trouble while trying to light this.
You seem to be bouncing back and forth between these two styles (sometimes lighting the forms as though they are three dimensional and sometimes lighting the forms as though they are fairly flat shapes (casting a shadow on the object directly behind it). It gets very inconsistent.
I think you just need to make yourself some rules about how you are going to handle light and form, and then stick to them.
Another minor crit is the cougar. I thought he was a bear at first. I know you want that warm, dark color so that he blends with the rocks and doesn't get noticed right away (and that part is working well). Maybe you can change his shapes so he's more obviously a cougar. The current shape of his back (silhouette) reads immediately as "bear".
I like what you have so far though. Keep going.
Agree with the Inspector... I remember the first time you posted a WIP for this and I think it is definitely improved since then. But if you compare the drawing style on the cowboy's face to that of the dog or the cougar, it looks totally different, so you should pick one. I like that paper cutout style you have going on with most parts of the drawing, so I vote for that. If you do go that way, it would look fine even if you just hinted at lighting since it's obviously a certain style you're going for.