Just played my first non-solo game of spirit island with my brother and my friend.
We ended up loosing and it was intense and awesome. It took most of the game for my brother and my friend to find their feet but once they did I could see the cogs churning away in their head as they began to see the depth to the game.
You really have to work at a very high level with everyone at the table to be effective, I feel like this game could be used to train teams of people its so intense.