Rocket Launcher:
Finish the game as Jill or Chris in under 3 hours. After the credits, a rocket will start to launch. Save the game to the memory card. Start a new game using the data off the memory card. When you check Jill's inventory, there is a rocket launcher.

Change Clothes:
Finish the game & rescue Chris & Barry or Jill & Rebecca. After the credits, You've got the special key, will appear. Save the game & start the game you just saved. Go into the room with a giant mirror from the main hallway & unlock the door in back.

Unlimited Ammo:
Just before the game says Resident Evil in the intro, hold Square, Triangle, R1, L1 & Select. Just after it says Resident Evil, while still holding the buttons, select Start or load & then press & hold Start.