To unlock the following, you must beat the respective tour of duty (US, Canada and Britan).
Effect - Code:
Unlimited Ammo - Beat the game on the Green Difficulty
Unlimited Grenades - Beat the game on the Veteran Diffculty
Unlimited Health - Beat the game on the Hardened Difficulty
Play and beat the game on Hardened Mode, then it will ask if you want to switch to survival mode. Select yes and it will switch to Survival Mode.
100.0% accuracy hint:
To obtain 100.0% accuracy on any level, have the "Unlimited grenades" cheat enabled. When you encounter enemies, toss plenty of grenades at them and hide. When all the grenades have blown up, check to see that no enemies remain. If there are, kill them with a rifle to maintain a high accuracy. After killing about thirty enemies with grenades, you should have 100.0% accuracy and should remain that way. If it does not, repeat the process.
Precise shots with Flak 88 in Walcheren:
During the "Walcheren" mission, find a Kar-98 scoped rifle (or any other sniper rifle) and keep it. When you reach the part where you must destroy the tanks with a Flak 88, switch your weapon to the sniper rifle and man the Flak 88, then press L to aim and go into sniper mode with the 88. You will be able to hit the tanks with a sniper's precision.
More than two guns glitch:
This glitch only works with a scoped rifle. Take out the scoped rifle and walk over a gun that you do not already have. Press L + RIGHT then repeat once to have three weapons.