Pause game play in Adventure mode then press Up(2), Down(2), Left, Right, Left, Right, B, A. to display the cheat code entry screen. Then, enter one of the following codes to activate the corresponding cheat function. Note: Some codes will disable achievements from being earned.
Unlimited secondary items:
Enter stevebrooks as a code.
Disable special tracking cameras:
Enter ihatefunkycameras as a code.
First person view:
Enter MorgyTheMole as a code. Note: Press Y to return to third person view, but without a head.
Enter upthejoltcola as a code.
Push objects away from player:
Enter southpeak as a code.
High pitched voices:
Enter chipmunks as a code.
Jennifer's chest is bigger:
Enter ArieannDeFazioWithFlair as a code.
Enter patrickdugan as a code.
Disable film grain visual effect:
Enter reverb as a code.
This can be performed with one or more players. When you are on the bridge going to the police station and you get the go-cart after the scene with the bikers, get into the passenger left side. Keep pressing A and the go-cart will begin to go crazy all over the screen. Note: This may cause you to die if it goes too far under the ground.
Complete the following achievements to unlock Xbox Live Gamerscore points.
Fashion Show (70 points): Unlock every character costume.
Monsterologist (20 points): Unlock every Bestiary entry.
Maniac! (30 points): Kill 10,000 monsters.
Long, Hard Road Out Of Suburbiacheck (20 points): Travel 1,000 kilometers.
Archaeologist (45 points): Collect 72 Specialty Melee Weapons.
"It's Mine! ALL MINE!" (25 points): Collect 10,000 Monster Tokens across all characters.
Trap Assassin (15 points): In Zack's House, use your cunning to defeat all of the enemies with traps (on Thriller or higher).
Prowler On The Roof (15 points): Collect all weapon parts in Streets of Suburbia (on Thriller or higher).
Did Someone Order Chinese? (15 points): Find a way to deal with that pesky Granny evil cat shield (on Thriller or higher).
You Got Fur In The Hyperishdrive (15 points): Escape the garbage trucks of death without boosting (on Thriller or higher).
Junkyards Just Aren't The Same (15 points): Make a mad dash to Bob Zombie (on Thriller or higher).
I Said Turn Off Your Car Alarm! (15 points): Destroy all the pesky, loud cars in the Parking Lot with your mech (on Thriller or higher).
The Bodyguard (15 points): These gold zombies trust you with their life. Show them you mean business (on Thriller or higher).
When Household Appliances Attack (15 points): Show the monster masses that vacuuming can be fun by using excessive force (Thriller or higher).
Grumpy Old Man (15 points): Do not let the old man get hurt.(Thriller or higher).
Very Sneaky, Sir (15 points): Show them you are a ninja of the night when taking back what is rightfully yours (Thriller or higher).
Does Anyone Clean This Roof? (15 points): Collect all weapon parts on Hell School Rooftops (on Thriller or higher).
Exhumed (15 points): Smash all the gravestones in the hidden graveyard and survive the horror (on Thriller or higher).
Go, Speed Boater, GO! (15 points): Zeppelin Flyer X and The Leprechaun has challenged you to beat his record (Thriller or higher).
What's That Sound? (15 points): Why waste ammo when a massive, angry ball of death will do the work for you (Thriller or higher).
They Wouldn't Spend It Properly (15 points): Let the monsters know that you are looking after their best gold interests (Thriller or higher).
JAILBREAK! (15 points): There has to be something useful in the castle jail cells. (Thriller or higher).
We Don't Need No Stinkin' Ammo! (15 points): Complete the final showdown without buying more ammo (Thriller or higher).
I Think We're Being Followed... (15 points): Bring out the white knuckled driver in you and blast through the escape (Thriller or higher).
Honed Survival Instincts (10 points): See if you can get far enough going solo in the Co-op Dojo.
A Little Help Goes A Long Way (20 points): Grab some buddies and see how many waves you can wade through in the Co-op Dojo.
Killing Machine! (20 points): Get 50% of the total kills in a ranked FFA Deathmatch game.
Control Freak (20 points): Perform all flag captures in a ranked CTF match.
Are You Crazy?! (10 points): Frag 4 players in under half a second in any ranked match.
Monster Survival Guide Pays Off! (10 points): Try to win a 10 minute or longer ranked Monster Hunter game without being turned in a monster.
Master Of Your Domain (20 points): Enter and never leave the hill in a ranked King of the Hill match.
Leading Noobs To The Slaughter (20 points): Destroy the opposing team by having your team win with 100% of the kills in a ranked Team Deathmatch.
Your Kung Fu Is Strong (20 points): Defeat all challengers using only your melee weapon in a ranked FFA Deathmatch.
High School Flag Team Captain (20 points): Use the flag to kill 4 players in a single ranked CTF match.
Nice Guys Finish Last (20 points): Win a ranked friendly fire token race match without killing any other players.
Have Fun Cleaning The Grill! (10 points): Frag 20 players while driving a vehicle.
Dirty Deeds (10 points): Score 10 frags by summoning homing explosive zombies while in zombie form in a single ranked match.
Are You Related To A Belmont? (20 points): Score 30 monster stuns in a single ranked monster hunter match.
Demolitions Expert (20 points): Score all frags using only grenades in a single FFA Deathmatch game.
Additionally, there are eleven secret achievements, six of which are currently unknown.
Block Party! (25 points): Complete Chapter 1, Suburbia Nightmare.
Shop 'Til You Drop (25 points): Complete Chapter 2, Shopping Maul.
School's Out Foreva! (25 points): Complete Chapter 3, Hell School.
Graveyards Creep Me Out Too (25 points): Complete Chapter 4, Cemetery Scary.
Have Fun Stormin' the Castle! (25 points): Complete Chapter 5, Evil Castle.