You can use your gun to shoot the ending credits.
Game Shark Codes
Master Code (Must Be On) 0E3C7DF2 1853E59EEE8EFDFE BCD0A302
Infinite Health CEAFDF94 BCA9DB23
Max Recovery Aid CEAFDE76 BCA99CE6
Max Resuscitation CEAFDE72 BCA99CE6
Max Antidotes CEAFDE7E BCA99CE6
Max Tachyons CEAFDE02 BCA9C292
Max Points DEAFDF3A BC413102
Have Ampoule CEAFDE06 BCA99C84