During gameplay, type in these codes:
BEAGLE - God Mode
KICKASS - All weapons
GIVEBLOOD - Get blood
RESCUE - Rescue hostages
GETMEOUT - Warp to next level
INFRARED - Display hidden ares
GEEWHIZ - End game scene

Easter Eggs:
To play the secret character, Agent Squiggly, type SQUIGGLY at the select player
screen and press the up arrow.