Hey guys:
I've been plugging away at a background for my game, and after working at it for a while, I've stepped back and find myself just completely unsatisfied with the way it looks. I can't put my finger on what about it I don't like, I just feel like it's sloppy and not very convincing.
Here's what I have so far:

And here's how it currently looks in game:

Before I got started, I was already pretty frustrated with several other attempts. I dug around the internet, and one look that I particularly liked was Kenneth Fejer's backgrounds in this shot:

Unfortunately, I really can't put my finger on what I'm getting wrong here. Can anyone help me out and point me in the right direction?
Thanks so much, you guys!