Well the concept is nice, but excecution is lacking.

The ground level, hills and such, looks very very well. So doesthe fog, excellent.
Tho the grass you've putten there needs some work. Instead of putting it completely random, try putting some bunches of grass here adn there. Also, make a smaller version of the same grass, and put it around the current grass, to 'hide' the 2D shapes you see.
And the mountains in the back could use some work, well first of all, mountains usually doesn't consist of round stones (Maybe they do in LotR? cant remember heh), but also you have to make heights here and there, mountains ain't a straight line.
Ohh and the Light from Above, try making them twice as big, but reducing the colors, making it fade more. ^^
I won't comment the city, since you self said it isn't great, Though I do think it's kind of nice, except for the gate and the main castle
Heh, sorry if I were hard, but just trying to help you out
