why are all non-obscene games kiddie games

That's not what I meant, and that's not true. There are plenty of non-obscene games that my daughter would not like. Example: Rouge Leader. A completely non-obscene space game (unless you consider fantasy dogfighting obscene), which my daughter has absolutely no interest in playing.

I was at the E3 expo last year, before the GameCube was released, and I got a good sampling of the titles coming out for all of the new platforms. Based on what I saw, I deliberately chose the GameCube because its titles were primarily designed for and marketed towards the preteen and early teen audiences, and I wanted to get a console for my daughter. The amount of sex and violence in a video game does not determine its target market, the design of the gameplay does. And games like Luigi's Mansion are made for kids like my daughter. Monkey Ball is interesting because, although it is primarily made for kids, it can hook adults, too. Those games are rare and wonderful.