I just learned about Persuasion – the Game of Civic Engagement, which is put out by CTO, the Ontario Educational Communications Authority. In it, your avatar walks around a neighborhood and chats people up about a civic issue facing that neighborhood. It looks like the main mechanic for the game involves clicking on neighbors, which spreads information. Apparently, when enough information is spread, you have a better chance of making the civic change you want. (Interesting model of social change).
iCivics has a similar civic engagement game, Activate, which has a different model of social change, one that involves awareness-raising, fundraising, and pressuring officials.