This is coming along nicely.

Here are a few things that stuck out to me... I think the shadowing on the mountains is a little heavy and dark (at least for me). The scrub isn't bad, maybe try using a brush that's a little more 'scattered' to give it a bit more random look. You rivers seem to be 'floating' on top of everything else, you might try giving them a bit of a bevel to help with that.