Enable cheats
Go to the main menu then enter L, L, R, R, B, B, Y, Y, X, X. Now you will see a cheat menu in the game.

Healing falling teammates
If one of your teammates falls to the ground, throw a smoke grenade near him. Then, get your health packet out and heal him.

Extreme mode
Successfully complete the game under the hard difficulty setting to unlock the extreme difficulty setting.

Destroying armored vehicle or tanks
Use Jones to run up to the vehicle or tank. Lay an anti-tank mine next to it, in turn sacrificing jones Temporarily to take out the vehicle or tank. Use Jones to run close to the tank, then plant a C4. Throw a smoke grenade on the tank, run for the nearest cover, then blow it up.

Various Codes
From the main menu press the following sequence of buttons on the controller: Z, Z, Y, Y, X, X, B, B, Start, Start.

To access the cheat codes in CDS II you need to enter the game options menu and select the ?cheats? tab. From here you will have the following options:

Code - Effect

MISSION LIST - This allows you to play any level
TROOPER LEVEL - This increases the intelligence of your troop
NEXT MISSION - This skips to the next level in the game
INFINITE SAVES - This will allow you to save the game as many times as you like
ENEMY LEVEL IS ZERO - This will reduce enemies to their lowest level of intelligence
INFINITE AMMO - Your guns will never run out of ammo