Get Samurai Edge Weapon
Finish the game using either Jill or Chris in less than 5 hours
Get Real Survivor Mode
Beat the game 1 time with either Jill or Chris. Now items that are put into one box can only be taken out of that box.
Get Rocket Launcher
Finish the game using either Jill or Chris in less than 3 hours
New Outfits
Chris
Casual clothes:To wear Chris' casual clothes, simply beat the game with him once on any difficulty.
Clothes from "Code Veronica": Beat the game with Chris twice on any difficulty.
Jill
Army Fatigues: Beat the game with Jill once on any difficuly.
Nemisis Clothes: Beat the game with Jill twice to wear her street clothes from RE 3.
*You must use the costume key you are awarded at the end of each completion.
Get Invisible Enemy Mode
After finishing the game 2 times with Jill or Chris you get it
Get One Dangerous Zombie Mode
After finishing the game 1 time with Jill or Chris you get it
Get Other Features (Includes developer gallery & costumes)
Finish the game using invisible enemy in less than 5 hours
Unlimited Grenade Launcher Ammo
Step 1: Empty your inventory into an item box.
Step 2: Put the grenade launcher in your upper left item slot, grenade rounds to be duplicated in the upper right.
Step 3: Close the item box.
Step 4: Open the inventory and equip the grenade launcher.
Step 5: Open the item box and select the grenade rounds to be duplicated.
Step 6: Press the A button twice.
Step 7: Move the cursor to the grenade rounds to be duplicated in the item box.
Step 8: Press the A button twice.
Next, open the Item Box again, and put the Flame Rounds into the Item Box. Then, move the cursor to Flame Rounds (in the Item Box menu), and then press the A button. The cursor should move to the Grenade Launcher slot.
Press the A button again, and you should have 260 Flame Rounds.
Repeat the process as desired for any type of Grenade Rounds.
At first this cheat didn't work for me, but I must have been doing it wrong, so keep trying because this cheat does work.
Easy Way To Kill Tyrant
First get the 22. derringer magnum from the 001 room and save it for the battle with Tyrant. One shot kills anything including zombies , hounds , hunters and so forth.