Very nice! I like the color palette.
Maybe adding some roads would be nice to fill the terrain a little more and provide some connexions between the castles/villages.
I did think about trying to make a more featured terrain with some hills and rocky areas, but I tend to do what I can when I have time and that is always in short supply so it was a trade off between richer detail and time available.
This has such a great terrain feel to it, not sure how to explain it. It is in a sweetspot between realistic and cartoony that makes me think of old school RTS and other military like games. Love all the little details like clouds, trees and shadows. Ony quip is that the tarrain is rather flat and featureless. I really would have loved to see how you would have handled hills, mountains, rivers, canyons, etc.
The colors are not my style but I still love it! Good job :)