Ranting time:
First thing I noticed was the parkour, and how it's only connected to four of the islands. That gives those four players an advantage over everyone else. I think you should remove it. Second, the island is smaller than the actual islands themselves and you need to enlarge it. Look at all the other maps for a general idea of how to do so. The terraforming under the islands is poor and rushed and could use more work, custom trees would look a thousand times better than bonemeal'd, and the terraforming isn't very well executed.
I like the concept of the map, but the actual map itself could use more work. :P