The name "Island Jumpsz" comes from the fact that you're jumping over islands and the "z" is there for it to look a little different than any other title.
The map consists of a total of 12 islands with 11 running over Jump n reached. Please play the map in Adventure Mode / Gamemode 2 (Press the button at the start).
I would be happy if you can post your time when YOU finished the map, simply because I'm interested.