The people behind youth smoking prevention campaign Truth have just released their own message game for iOS: Graffiti Collective. The basic theme is that smoking is really bad for you and the American cigarette companies do lots of awful things to keep people smoking. BUT even people who smoke like a hundred packs a day might just dig this free game's actual gameplay. As you can guess, it involves lots of awesome graffiti.
I like to think that games qualify as art. And like art, some games seek to promote messages rather than simply entertain. Not everyone will agree with what a message game has to say, but that’s how art works too.