My favorite part is the water, I think you got that just right with the gradual fading.
I'm not sure I see what others are saying about the zoomed out/zoomed in issues. Maybe my monitor is a different shade or maybe my old eyes are just not as good as they used to be. That said, I've seen many maps that either looked amazing zoomed out but where half rubbish zoomed in and vice versa so I guess it depends what the viewer is supposed to be looking at. I'm sure it can't hurt in the voting if the thumbnail looks amazing but anyone who judges these by only looking at the thumbs must be whack-a-doodle because you won't see any of the details all of these entries have.