Call of Duty 2 Cheats

Level select
Hold [LB] + [RB] then quickly press [Left], [Left], [Right], [Right], [Y], [Y] at the mission selection screen.

Unlimited Ammo
Enter the code below on the main menu to unlock unlimited ammo:

[Left], [Left], [Left], [Right], [Left], [Right], [Yellow], [Yellow]: Unlimited Ammo

Achievements
Play a Single-Player campaign mode and accomplish a certain task to unlock these achievements for Gamerscore points:

Completed Training (50 points): Complete the Basic Training Level
Veteran of Crossing the Rhine (60 points): Complete Crossing the Rhine levels on Veteran
Veteran of D-Day (60 points): Complete D-Day levels on Veteran
Veteran of El Alamein (60 points): Complete El Alamein levels on Veteran
Veteran of Fortress Stalingrad (60 points): Complete Fortress Stalingrad levels on Veteran
Veteran of Hill 400 (60 points): Complete Hill 400 levels on Veteran
Veteran of Rommel's Last Stand (60 points): Complete Rommel's Last Stand levels on Veteran
Veteran of Stalingrad '42 (60 points): Complete Stalingrad '42 levels on Veteran
Veteran of The Battle for Caen (60 points): Complete The Battle for Caen levels on Veteran
Veteran of The Tank Squadrons (60 points): Complete The Tank Squadrons levels on Veteran
Veteran of the Winter War (60 points): Complete Winter War levels on Veteran
War Hardened (200 points): Complete the game on Hardened or Veteran with all levels complete
Won the War (150 points): Complete the game on any difficulty with all levels complete