Note: This game is also known as - Biohazard

Hard mode - Successfully complete the game on the Normal difficulty to unlock the Hard difficulty.

Invisible Enemy mode - Successfully complete the game three times on the Normal or Hard difficulty to unlock Invisible Enemy mode.

One Dangerous Zombie Enemy mode - Successfully complete the game with Chris and Jill to unlock One Dangerous Zombie Enemy mode.

Real Survival mode - Successfully complete the game twice on the Normal or Hard difficulty to unlock Real Survival mode.

Alternate title screen - Successfully complete the game to alternate the title screen.

Bonus weapons - Successfully complete the indicated task to unlock the corresponding weapon:

Rocket Launcher: Successfully complete the game on the Normal or Hard difficulty in less than three hours.

Samurai Edge Handgun: Successfully complete the game on the Normal or Hard difficulty in less than five hours.

Successfully complete the indicated task to unlock the corresponding alternate costume:

Chris' alternate costume: Successfully complete the game with Chris.
Chris' Resident Evil: Code Veronica costume: Successfully complete the game twice with Chris.
Jill's alternate costume: Successfully complete the game with Jill.
Jill's Resident Evil 3: Nemesis costume: Successfully complete the game twice with Jill.

Successfully complete one of the following tasks to change the ending sequence:

As Chris, let Jill and Rebbecca die at the Heliport.
As Chris, let Rebbecca die, but rescue Jill.
As Chris, let Jill die, but rescue Rebbecca.
As Chris, rescue Rebbecca but let her die at the Heliport, and rescue Jill.
As Chris, rescue Rebbecca and keep her alive, and rescue Jill.
As Jill, do not give Barry his gun and do not rescue Chris.
As Jill, do not give Barry his gun and rescue Chris.
As Jill, give Barry his gun and keep him alive, and rescue Chris
As Jill, give Barry his gun and keep him alive, but let Chris die.
As Jill, give Barry his gun back, let him die at the heliport, but keep Chris alive.