Extra Characters in multi-player game
The cheat to unlock the final stage, The Way Home will also unlock all the extra characters in the mutli-player game. Enter 'VRCLN' at the 'Input Code' screen found on the Main Menu.

Level Select
Enter at the input code area on the opening screen:

Stage 1 TRGHTR Stage 9 GNRLMN
Stage 2 TDBWL Stage 10 HTTTRT
Stage 3 MSTRMN Stage 11 ZBTSRL
Stage 4 TLLTRS Stage 12 HTKTTN
Stage 5 SCRDCT Stage 13 PTSPNS
Stage 6 STPDMN Stage 14 HXMSTR
Stage 7 BLZZRD Stage 15 VRCLN
Stage 8 SRFPNK Stage 16 BTTLN

All characters
Enter BTTLN as a password.

Mini mode
Enter DRVLLVSMM as a password.

Making of sequence
Enter SFFRMV as a password.

Test information
Enter THDTST as a password.

Unlock Facial Textures
Password - Granted Effect

FCFJHNRN - John Ren
FCHL - Hal
FCDRCMOCAM - Mitchell
FCFBRN - Bryan
FCFJHNN - Johnny
FCFMK - Mike
FCFRCHRD - Richard
FCFSTV - Steve
FCFBRNT - Brent
FCFCMCOTEAH - Roger
FCFRBN - Robyn
FCFSTWRT - Stewart
FCFTDD - Todd
FCFJN - Jun
FCFKTH - Kathy
FCFJRM - Jeremy
FCFDNN - Danny
FCFBRD - Brad
FCFDSTN - Dustin
FCFCRRRNSTRM - Carre Renstrom
FCFRNNX - Ryan Nix
FCFTLRRNSTRM - Tyler Renstrom
FCFMGNRNSTRM - Megan Renstrom
FCFNKKN - Nikki Pino
FCFLXSPN - Alexis Pino
FCFCHDRBRTSN - Chad Robertson
FCFBRTNGN - Brien Atangan
FCFVRGLBD - Virgil Abad
MDWTSTNG - Midway Testing

All Weapons
Enter the code 'NSRLS'.

Maximum Ammo
Enter "MMLUSRM" as a password.

Tin Foil Mode
Enter "TNMN" as a code. Note: This is not armor, although there is a resemblance.