From the introduction:
It's the 70's! But nobody gives a shit about bellbottoms, leisure suits, or disco. In Mexico, the only things that matter are money and family. While gang warfare amongst the lower class was in its infancy in the U.S., it was a way of life for generations down here. If you were lucky, you were a good mariachi player. Nobody likes to let a good mariachi go to waste.
In Mexico 1970, you play the part of a middle-to-lower class Mexican (or Gringo if you're unlucky). Though your purpose is to make a better life for your self, you find the better part of your time spent just surviving. Guns blaze and children die. The old west is alive in the 70's right here in Mexico, except now there are cars and better guns. Not a good mix if you’re the suburban type.
Generally, the big cities are avoided to maintain anonymity. It’s a good thing, too. The more anonymous you are - the more invisible you are.