Homage to Gradient - WIP

This is a Homage to the great artist Gradient, for many reasons. I have gotten inspiration on this piece for both the POV and sky, but I also used a technique that he gave in the hints thread for rendering the sky later, which really was helpful here.
It is a work in progress, because I'd really like to make this better, and fine tune things, so all advice is really welcome.

Thanks for Mayday for her terrain and Overlay.
t4v
Sacha