One of my most popular videos is Professor Garfield: Fact or Opinion?. It consistently gets over a thousand views a month. Why? I'm not sure, but I'm told that it's on some standard elementary school syllabuses. I find it AMAZING that kids are watching this for school, considering that I insult the false fact/opinion dichotomy that the game promotes.
So I played the other three games in the series. They aren't as popular, but maybe they'll get put on school syllabuses too, someday.