Heifer Village: Nepal is an interactive simulation to help students think about poverty and community development. In some ways, it's similar to Third World Farmer, but it's more of a simulation than a game, if you want to get into semantic differences.
What I like about Heifer Village: Nepal in particular is that it leads participants through the steps and thought-process of developing a community-centered micro-loan organization. Through this structured simulation, participants can see the benefits of impoverished communities banding together to help each other out. I have dreams of getting students involved in providing micro-loans to such organizations themselves, through groups such as Kiva. (I hope you'll check out Kiva and think about how this organization might help you broaden your students' global view!)
In any case, a simulation like Heifer Village might be the first step. Check it out!