ive played this game a lot and i have made a house rule that whoever has never played the game before gets to set up the tiles however they like so as to create a new island each time. If there is nobody who hasnt played then i close my eyes and set it up by feel into a random shape.
every game is different, but we have the same win/lose ratio as playing with a boring diamond.
i think it has to do with how tiles disappear throughout the game anyway, so a new shape only makes it more exciting.
Nice way of doing the setup. Just have to be a little creative and try to make the game even harder.