Access the cheat menu:|
In the options menu, go to player name. On there,
put name either Go Postal for something
Fox Rox for something else
Godzilla for something better
Tourist for something stupid
Which ever one you use, go to the Start Game Multiplayer, and options screen. As soon as you see the flag on the moon movie quickly type Left, Right, Up, Down, X, Z, Y. You'll be transported to a cheat menu.
At player name screen type Mr Happy. At the main menu quickly press Left, Right, Up, Down, X, Z, Y
Go to player name in the options menu. Then, put your name in as Credits. Go to EXIT, and watch the credits roll by.