I just found out about Unicef Games, a small but growing game portal for the well-known advocacy and fundraising organization (thanks to Barry). It seems Unicef has created two games so far, World Heros and Halloween Coin Toss.

Halloween Coin Toss is quite simple and really has nothing to do with advocacy at all. The player tries to toss coins into Unicef-marked boxes posted near local merchants. I suppose the game helps kids understand that such boxes exist so they can encourage their parents to give them a coin to drop in when they see one.

World Heros is a more extensive game, with quite high production value, especially art and sound design. The game allows the player to volunteer on a variety of Unicef relief missions, including immunization, water purification, and nutrition. While the environments change on each mission, the gameplay is the same: the player drives a Unicef truck around to catch iconographic representations of Unicef relief that a Unicef plane airdrops. I think the idea is to give kids an understanding of the kinds of relief efforts Unicef organizes and the various types of relief necessary in each (e.g., bottled water and medical kits for earthquake victims).

All in all, these games aren't terribly sophisticated in their representation or encouragement of advocacy. That said, they do seem to be designed for very young children, and I can imagine that they might be beneficial conversation starters in such a context. If you have kids who occasionally pester you to play Sesame Street games on PBS Kids, World Heros might be a satisfying replacement that could engender some out-of-game discussion.