Start the game and type in these cheats in the cheat box (note - it will not say cheat enabled or anything):
NOHIT - Invincibility
MOREAMMO - Infinite Ammo
POINTER - Adds a Laser Sight
FASTFIRE - Shoot very fast
Take on some of the quickest gun slingers in the world and kill them all.
Use the hack codes to improve your chances and keep you alive longer.