Freodin makes some good points about the layout and design elements quite right.
Also, it's unclear what the Colistair Empire is. I'm assuming it's the political entity that rules all the places shown on the map, but judging by both the font you've used to label it and its location on the map, it looks at first glance as if it refers to the northern body of water. To fix this, you may want to consider putting it in a different font, and moving the name so that it covers the land the empire controls.
A more minor stylistic point: the transition between green and the yellow is quite abrupt. There are a couple of instances of mapping styles where this would be justified, for instance, if the green is supposed to represent the border of the region of Molur and the rest of the world (similar to how the countries are in this map), than this is fine, although you may want to change the yellow to a different color, such as grey. However, it rather looks instead like the green and yellow represent climates, grassland and desert respectively. If this is the case, you may want to feather the border between them some more to imply more of a gradual transition.