The islands dont look natural, they are square, and the "mountains" on the islands are almost like staircases. The islands are all very boring, just grass with some chests. Try to add stuff like trees, tall grass, flowers or even rocks/caves to make the islands a bit more interesting.
The islands arent in a circle around the middle one, giving some people an unfair advantage over others (and driving people with the slightest case of OCD insane.) But thats not the biggest problem because builders can easily correct this if the map where to be implemented.
Overall I'd say the idea could be nice, a bit more of a simple map, that's all about the PvP, not just pretty islands, but it doesnt hurt to make s imple map look pretty.
Keep improving!