Special rifles - You got to create a new profile and
enter the following codes as your profile name.
Note: If you do this, your score will be 0. No matter what you do.
Password Effect
Panzer Explosive bullets for your rifle.
Ratbomb Rats explode when shot
Stealth Silenced rifle.
Unlockables
Secret Mission - This can be done
under any difficulty section
++Secret mission Beat the game