RocketGrunt - It's a good start but a lot more things can be done to make the screen look good. Like Moosh said, there's a lot of straight lines everywhere. To try and make this look as natural as possible you gotta have jagged lines (in other words, try not to make things straight). Probably scatter the bushes around a bit and give the mountain a bit of a curvature rather than being completely straight. So yeah, straightness is my main problem here.
Shane - Hot damn, that's some amazing stuff. Like I said elsewhere, those side mountains near the water can use some work, but other than that, this is one hell of a unique artstyle and could easily pass off as an SNES game or something. Amazing work.
Saffith - Very nice and simple. The screen is very well done and I do like the multiple levels of elevation over to the top-right side.
Joelmacool - That's one trippy palette. I like what you were going for here though, I find this screen to look really nice. Good job!
I voted for Shane this week, I want that tileset now ;_;