Lots of work needs to be done for this map to be implemented, in my opinion. Here are some things I thought of to improve on:
-Add some detail to each player island to make them all stand out. They all look extremely similar.
-Right now, things look very boxy, especially the windmill in the middle island. Try to add some depth to ir, or use some block variation in that windmill.
-Lastly, like others have suggested, add some more color to the map in general. It is quite bland right now.
After you make some improvements, post some new screenshots or a new video. :D
-Simbaaa