The World Peace Games looks like such an incredible learning tool. Matt plays something similar (although less detailed) called 'the trading games' with his geography students. I'd love to find a way to get enough homeschooled children together that we could take a few days and play this out properly.
The rules state that you can't win the game unless all 50 global problems are solved (issues like global warming, racial inequality, famines etc...) and all of the countries increase their assets (naturally the poor get poorer unless there is some form of coalition/intervention which the children have to come up with by themselves).
The website is here if you want to know more, I personally cannot wait until my children are old enough to take part in something like this. This kind of learning is why we home educate.