most of that stuff is up to the publisher, for example valve made half life 2 vivendi produced it, so vivendi chose how it would be sold and all that stuff. The publisher also has control over the conten because they can basically say "we don't like this part, take it out or find another publisher"
esrb does do the ratings, but those ratings mean squat pretty much, in most places there are no laws connected to the ratings on video games, as of right now they are just suggestions(a lot of stores enforce to some degree, but that is their option),
The Entertainment Software Association (ESA) is the U.S. association exclusively dedicated to serving the business and public affairs needs of companies that publish video and computer games for video game consoles, personal computers, and the Internet. ESA members collectively account for more than 90 percent of the $7.3 billion in entertainment software sold in the U.S. in 2004, and billions more in export sales of U.S.-made entertainment software.