The thing that leaps to the eye, is the choice of this red so intense for the labeling of the major geographic regions of your kingdom. I would say that a choice of a less vibrant color could be better; you can also try to play with transparency and maybe decrease the size of the labelling. Maybe the green of the swampland is too intense, but that can be an already more passable artistic choice, in my opinion.
Being the representation of a swamp land, I find it acceptable that there are no mountains; the water streams (are they mainly rivers? Or are there also some creeks?), though, seem to come out of nowhere; ok, I'm not an expert in marshy regions, but something tells me that the hydrography of the water courses must be reconsidered, especially the waterways.
I like the idea of the shields; I would also add a border to the map.