Overall great looking piece. Some colors are not really needed but that's just nitpicking. I do agree with zi-double's view that the shadows are inconsistent in many places.
maybe must try your dark green for the grass to be more dark for good contrast and can repair many little places as upper part of the tower in the dark side need some details the shadow under the door isn't proper and many other - but very nice vision and idea I see in that work !
Want to give some dough back to all those amazing pixel artists? Donations provide prize money for contests, help cover hosting costs and support new initiatives.
Nice stuff!