I really like the way you did the terrain. The oceans are great, and it's got a very consistent feel to the palette throughout. Overall I'd say great work.
There are only two things that stand out to me while I look it over. The text for the northernmost town blends a little too closely with the background colour, kind of loses itself in the terrain. The second thing I notice really stands out in the thumbnail moreso than the map itself - the different regions have a very straight banding across the land. I'm guessing there's a gradient involved in setting the colours from north to south? If you broke those colours up a bit to make it less obvious that might help it look a bit more natural.
how DID you do the terrain/mountains, anyhow? I *really* like that.