Not sure you're helping yourself here. The established movie industry uses its content rating system as a bludgeon against independent filmmakers. The video game industry's content controls are largely a joke, assigned arbitrarily by people who never actually play the game.

which are pretty much a joke. PG is now a worthless rating

http://www.forbes.com/sites/scottmendelson/2013/11/26/disney...

The difference between PG-13 and R in many cases is completely arbitrary.

The ratings lump many kinds of movies together and says absolutely nothing about their content.

No movie can be NC-17 or unrated because that is a kiss of death. No theaters will play it, no big box stores will sell it. I think what R can get away with has broadened considerably because of that.