This is absolutely beautiful, in a muted sort of way. Moody, sparse, with a sense of great expanses which many maps never quite convey. Bleak and windswept, indeed.

Looking at this in detail, I like just about every element--the color and shapes of the forests, and the clear distinction between deciduous and coniferous trees; and especially the mountains and hills. Ordinarily I don't like sharp, pointed mountain-ridges, but these look great.

I assume your client supplied you with the names? I notice the cities are "Bantho" on the western shore of the Me Mievnoke Sea, and "Batho" to the east, and I'm assuming that difference is grounded in the setting.