Infinite Ammo
Start a game and press Select to display the options screen. Select the "Key Config" option, then hold R1 and press Square(10x). If you entered the code correctly, the word "Auto" will turn red.

Extreme Battle/Survival Mode
Beat the game with Leon, then save the game. Then, play Claire's second scenario, beat the game, and save the game.

Bonus Weapons
Beat either character's first scenario in under two hours and thirty minutes with an A or B ranking for the rocket launcher with infinite ammunition. Beat either character's second scenario in under two hours and thirty minutes hours with an A or B ranking for the gatling gun with infinite ammunition. Beat either character's second scenario in under three hours with a A or B ranking for the machine gun with infinite ammunition. Note: The bonus weapon will appear in the next game after the first chest is opened.

Play Hunk Scenario
Beat Claire or Leon's second scenario saving less than twelve times with a end time of under two hours and thirty minutes. Hunk is a soldier that must reach the second floor of the police station from the sewer with just battles and no puzzles.

Play Tofu Scenario
Beat either character's first and second scenarios in less than three hours. Then, play the game again with the other character, and also complete their first and second scenarios in less than three hours. Play the game a third time and complete either character's first and second scenarios again in less than three hours. Note: The game must be saved less than twelve times during each of the six scenarios played and bonus weapons must not be used. Tofu is a piece of tofu (food) that must reach the second floor of the police station from the sewer with just battles and no puzzles. Tofu can not use any weapons other than a knife.

Alternate Uniforms
Start a game on the normal difficulty setting. Then, go to the police station without collecting any items. Quickly move past the zombie that appears in the alley near the police station. Collect the shotgun, then kill the zombie. Take the special key from the zombie's body and go to the dark room to open the lockers with alternate uniforms. Claire has a single alternate uniform, with a quick shooting revolver. Leon has two alternate uniforms, one of which will allow him to shoot with one hand.

Easy Kill Gator
When fighting the gator, and he starts coming towards you, go and inspect the yellow light on the left wall. Then, the light will fall and the gator will eat it. Now while the light is in its mouth, shoot it and the gator will explode.

Ranking System
Normal
1 1/2 hours, No saves, No infinite weapons, No first aids, No mixed herbs = "S"
1 1/2 - 2 1/2 hours 1-3 saves, 1-2 first aids, No infinite weapons = "A"
2 - 3 hours, 1-7 saves, 1-4 first aids, No infinite weapons = "B"
2 - 3 hours, 1-5 saves, 1-3 first aids, infinite weapons = "B"
3 - 4 1/2 hours, 1-7 saves, 1-7 first aids, No infinite weapons = "C"
3 - 4 hours, 1-7 saves, 1-6 first aids, infinite weapons = "C"
4 1/2 hours & up, 8 or higher, 6 or higher, infinite weapons = "D"
4 1/2 hours & up, 7 or higher, 6 or higher, No infinite weapons = "D"

Easy
Under 2 hours, 1-2 first aids, 1-3 saves, No infinite weapons = "A"
2- 2 1/2 hours, 1-4 first aids, 1-3 saves, No infinite weapons = "B"
2- 2 1/2 hours, 1-2 first aids, 1-2 saves, infinite weapons = "B"
2 1/2 - 3 1/2 hours, 1-5 first aids, 1-8 saves, No infinite weapons = "C"
2 1/2 - 3 1/2 hours, 1-4 first aids, 1-6 Saves, infinite weapons = "C"
3 hours or higher, 5 or higher, 9 or higher, infinite weapons = "D"
3 hours or higher, 4 or higher, 9 or higher, No infinite weapons = "D"