Small but disastrous changes to famous video games was the topic, and I *highly* suggest you check out the other submissions too, there were some brilliantly silly ones in it. :)

"You don't know Jack" is one of the funniest multiplayer games I ever played. It puts you into a virtual quizshow in which you try to answer trivial questions. The fun comes from the presentation - the show of course has a showmaster too, and that guy is just hilarious!

Of course it wouldn't be as much fun if the questions were much, much harder...