Veteran mode:
-------------
Reach Level 32 to unlock Veteran mode, which is a Co-op mode with much tougher
enemies.

Zombie mode:
------------
Successfully complete Campaign mode to unlock Zombie mode, which is a
four-player Co-op mode against endless waves of Nazi zombies.

Ray Gun in "Little Resistance" mission:
---------------------------------------
After the boat crashes, call in an air strike on the specified location. Run up
to the beach, and move to the right. You will find a small puddle at the right
side of the beach. Stand in it briefly, then move towards the middle of the
beach to find a smaller puddle. Stand in that puddle briefly. Move towards the
far left side of the beach. Stand briefly in the puddle in the barb wire. After
several seconds, the screen will shake, and you will hear strange voices. Four
lion statues will rise out of the ground with alien Ray Guns in their mouths.

Extra ammunition:
----------------
Use the following trick if run out or are running low on ammunition on any
mission in Solo mode on any difficulty. Find a non-essential teammate (someone
not involved in the story line). Walk up to him, and aim the reticule next to
his head or torso. Knife the air, and as you do so move slightly towards them so
that the reticule is over them. If done correctly, he should die and drop his
weapon. Non-essential teammates will get replaced when you walk into a battle.
If the teammate does not die but keeps getting back up, they are essential to
the story (for example, Sgt. Roebuck and Sgt. Rezenov).

Hidden radio music in Nacht Der Untoten:
----------------------------------------
Start any type of Nazi Zombie game, and unlock the door to the Mystery Box room.
Go to the Mystery Box. Go over to the right, and look at a table to find a
radio. Shoot a bullet at the radio. After a few seconds, you will hear random
types of music such as rock, disco, opera, and some in-game music such as the
Russian victory song, the final mission music, or the Japanese combat music. The
music will stop in between rounds but will then start again. Every player in
game should hear it.

Easy "Gunslinger" achievement:
------------------------------
After you get to the sniper spot to kill General Amsel, shoot all your pistol
ammunition. Then, switch to your sniper rifle, then switch back to your pistol.
You should now have 80 rounds of ammunition instead of only 13.

Easy "Rough Economy" achievement:
---------------------------------
Play the "Vendetta" mission. After you shoot General Amsel's guards and move up
to the car with the sergeant, a group of Nazis will appear down the street. Do
not follow the sergeant. Instead, stay near the car, and wait for three of the
Nazis to get in a line, then shoot.

Achievements:
-------------
Complete the following achievements to unlock Xbox Live Gamerscore points.

Carlson's Raiders (10 points): Complete 'Semper Fi' on any difficulty.
(Solo only)
Stormed Peleliu (15 points): Establish a beachhead on the island of
Peleliu on any difficulty. (Solo only)
The Last Stand (20 points): Survive the land and air conflict surrounding
Okinawa on any difficulty. (Solo only)
Stabbed in the Heart (20 points): Complete all missions on the Eastern
Front on any difficulty setting. (Solo only)
Get Your Hands Dirty (30 points): Complete 'Semper Fi' on Veteran difficulty.
(Solo only)
Saved Private Ryan (10 points): Save the soldier before he burns to death.
(Solo or co-op)
Bloody Peleliu (30 points): Complete 'Little Resistance' on Veteran difficulty.
(Solo only)
Weapon of Mass Destruction (15 points): Radio in a naval bombardment that
kills at least 4 Japanese soldiers. (Solo or co-op)
The Sword Is Broken (30 points): Complete 'Hard Landing' on Veteran difficulty.
(Solo only)
No Safe Place (15 points): Burn an enemy out of a tree with the flamethrower
in 'Hard Landing' (Solo or co-op)
Architect (30 points): Complete 'Vendetta' on Veteran difficulty. (Solo only)
The Professional (15 points): Shoot all of Amsel's henchmen, including their
attack dog, without reloading. (Solo only)
Gunslinger (15 points): Assassinate General Amsel with a pistol shot.
(Solo only)
The Hammer Strikes (30 points): Complete 'Their Land, Their Blood' on Veteran
difficulty. (Solo only)
Scorched Earth (30 points): Complete 'Burn'em Out' on Veteran difficulty.
(Solo only)
Firestarter (15 points): Complete a mission using only the flamethrower.
Melee, grenades and explosives are OK. (Solo or co-op)
Fearless (30 points): Complete 'Relentless' on Veteran difficulty.
(Solo only)
Hell on Wheels (30 points): Complete 'Blood and Iron' on Veteran difficulty.
(Solo only)
Iron Fist (15 points): Destroy all towers and bunkers in 'Blood and Iron'.
(Solo or co-op)
No Return (30 points): Complete 'Ring of Steel' on Veteran difficulty.
(Solo only)
Ruthless (15 points): Kill 15 enemies while mounted on a tank in 'Ring of Steel'.
(Solo or co-op)
When It Rains, It Pours (30 points): Complete 'Eviction' on Veteran difficulty.
(Solo only)
Shot in the Dark (10 points): Kill 10 enemies while the lights are out in
the subway in 'Eviction'. (Solo or co-op)
One Bad Gato (30 points): Complete 'Black Cats' on Veteran difficulty.
(Solo only)
The Sum of All Zeros (15 points): Down 45 Japanese Zeros in 'Black Cats'.
(Solo only)
Lights Out! (10 points): In 'Black Cats', blast out all of the spot lights
in the Japanese cargo convoy. (Solo only)
Blowtorch & Corkscrew (30 points): Complete 'Blowtorch & Corkscrew' on
Veteran difficulty. (Solo only)
Setting of the Sun (30 points): Complete 'Breaking Point' on Veteran
difficulty. (Solo only)
Mortar-dom (10 points): Kill 8 Japanese with thrown mortars in 'Breaking Point'.
(Solo or co-op)
Guardian Angel (10 points): In the final battle for Okinawa, save Sergeant
Roebuck. (Solo or co-op)
For the Motherland (30 points): Complete 'Heart of the Reich' on Veteran
difficulty. (Solo only)
Bearing the Burden (30 points): Complete 'Downfall' on Veteran difficulty.
(Solo only)
Rough Economy (15 points): Kill 3 enemies with a single bullet.
(Solo or co-op)
Close Shave (10 points): Survive a Banzai attack. (Solo only)
Snake in the Grass (15 points): Take out a Japanese soldier while he is lying
in wait in the grass. (Solo or co-op)
Grave Robber (15 points): Collect all Death Cards in the game. (Solo only)
Kamikaze (15 points): Complete any level on Regular difficulty or higher
using only melee and grenades. (Solo only)
Throw a Six and a Half (15 points): On Hardened or Veteran difficulty,
complete a level without dying. (Solo only)
Purple Heart (5 points): When staring into the face of adversity, show
courage and persevere.
War Hero (40 points): Complete the game on any difficulty. (Solo only)
Hardened War Hero (100 points): Complete the game on Hardened or Veteran
difficulty. (Solo only)
Get Your Left Foot Wet (30 points): Complete a match in Campaign Co-Op mode
over Xbox LIVE. (Online co-op only)
Get Your Right Foot Wet (30 points): Complete a match in Competitive Co-Op
mode over Xbox LIVE. (Online co-op only)
Blue Ribbon (25 points): Complete a 4-player Competitive Co-Op match in 1st
place over Xbox LIVE. (Online co-op only)

Additionally there are two secret achievements.

Secret achievement (0 points): Unknown.
Secret achievement (0 points): Unknown.