Secrets, Unlockable

Leech Hunter Mini Game: Beat the main game on any difficulty to unlock this game.

To obtain the train's closet key, which is used to alter Rebecca or Billy's costume, beat The Leech Hunter mini game with either an A, B, or C ranking. 

To obtain the machine gun, closet key and unlock Leech Hunter mini game: Beat the main game with an A ranking.

To obtain the rocket launcher, machine gun, closet key, and Leech Hunter: Beat the main game with an S ranking.  Not easy!

Leech Hunter mini game unlocks:

• Unlimited ammo in the main game: Beat the game with all 100 leech charms
• Unlock machine gun ammo for the main game: Collect between 1-29 leech charms
• Unlock the magnum revolver for the main game: Collect between 90-99 leech charms
• Unlock unlimited both handgun ammo for the main game: Collect between 30-59 leech charms
• Unlock unlimited ammo for the hunting rifle for the main game: Collect between 60-89 leech charms

Unlock alternate costumes: Beat the main game on either Normal or Hard mode.  The closet key becomes available in Rebecca's inventory upon starting the next main game.

Skipping the first leech zombie battle: In the second floor bar at the rear of the train, you'll be confronted by the first leech zombie.  Once the cutscene is over, just go back down the stairs and another cutscene will activate, causing Billy to kill it without having to do it yourself.

Glitch with the PS4 version: In the water treatment plant, right after Rebecca takes the lift downstairs, when she changes the camera angle, she can lure the zombies back to the area near the lift. However, the zombies will not be able to enter the camera frame close to the lift. She can stand at that position and continue to knife the two zombies without getting injured or hit even once. Similarly, in the steam room in the water treatment plant with the lift, position Billy or Rebecca near the lift facing toward the screen. Have your character stand next to the dangling florescent tube and lure the zombies to come from the door. The zombies will get stuck at the corner of the railing and can be stabbed until they are all dead. This helps to conserve ammo.

HD Remaster Mode: Unlock Wesker Mode: Beat the main game.