Hi Moros, nice first map.
I think the deserts would look better if they were lower opacity. You could try playing around with the blending mode for it (e.g. multiply, soft light) but I have no idea if one would look good. It also really needs some blending around the edges, so it looks like it fades into desert.
The mountains could a bevel to make them look 3d also.
I hope that helps.