It looks really cool, colourful and creative. However, from a PvP point of view and playability, it's fairly annoying especially for EggWars. Remove all the grass (31), this allows players to be able to place blocks anywhere on the surface of the island. The Island NEEDS to be flat, at the moment, it is 4/5 block indent which is annoying for a user to have to climb just to get inside. In any fight you want it to be near enough flat, than climb a hill. Change the brown dome mushroom, to any other kind of mushroom, just looks unrealistic as a mushroom. And one last little nitpick, can you make the trees smaller/shorter, just to reduce players camping on tall areas to drag out the game.
Anyways, love the colours and the layout, just focus on making the islands flatter so it drastically improves gameplay.