Enter the character selection screen and press Delete, then enter one of the following codes and press Enter:
All levels, cities: itsgallus
No police: iamthelaw or stevesmates
999,999,999 points: itcouldbeyou
All weapons, armor, "Get Out Of Jail Free" card: suckmyrocket
Infinite lives: itstantrum
Raise point values: hatemachine
View FMV sequences: heartofgold
Press Keypad Asterisk for all weapons: callmenigel
Enable extra offensive language: iamgarypenn
Disable extra offensive language: iamnotgarypenn