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.

Cheat code:             Effect:
Ratbomb                 Rats explode when shot
Panzer                  Explosive bullets for your rifle.
Stealth                 Silenced rifle.

Bonus mission
     Successfully  complete  the  game  on  any  difficulty setting to
unlock a bonus mission.