Infinite Items:
Whilst playing go to the inventory screen. Go to the Timex. Now press and hold L1, L2, R1, R2 and Down followed by Triangle. If you now leave the inventory and return a second time, you'll find all items.
All Weapons, Ammo, Medipacks:
Whilst playing go to the inventory screen. Go to the Timex. Now press and hold L1, L2, R1, R2 and Up followed by Triangle. If you now leave the inventory and return a second time, you'll find all weapons with unlimited ammo and all medipacks.
Special Features:
Whilst playing go to the inventory screen. Go to the Timex. Now press and hold L1, L2, R1, R2, Down and Circle followed by Triangel. Leave the inventory and quit the game to find all extras enabled.
Russian Base:
To load the first level of Russian Base select New Game on the main screen. Then press and hold L1 and Up followed by X.
Ireland - Black Isle:
To load the first level of Black Isle select New Game on the main screen. Then press and hold L2 and Up followed by X.
VCI Headquarters:
To load the first level of VCI Headquarters select New Game on the main screen. Then press and hold R1 and Up followed by X.