Hmmm, before I recommend for gameplay I will say something about the scenery on your map
+ I like the sun behind the clouds
- The castles dont look like castles, it are towers, and even a tower has stonewalls, maybe use some scenery
fitting best the theme
- this island in the middle could have more vegetation, if you really want to have a dead tree there you should
recolor it to a "dead" color (some brown mixed with yellow or sth else)
I will come to gameplay, when I´ve tested your map