Maximizing Leon's life bar:
Note: This requires several continues, which doesn't affect the game's ending. At the first El Gigante fight, there is a Yellow Herb in the boss arena. Take this item and combine it with any of the Green Herbs in the same room and use it. This will increase Leon's lifebar slightly. Now let the boss kill Leon. Since the boss' room is at a map transition (the green OPEN command is a dead giveaway), this allows you to proceed right at the boss fight but with Leon's life increase from your previous attempt. Repeating this process will increase Leon's lifebar to maximum prematurely. Extra Yellow Herbs found later can be given to Ashley, or sold to the merchant for money
Unlockable "Mercenaries Mode" Characters:
Unlock the following characters for Mercenaries mode by performing the corresponding tasks:
CHARACTER - HOW TO UNLOCK
Ada Wong - Earn a four star rank or better on the Pueblo map.
Albert Wesker - Earn a four star rank or better on the Waterworld map.
HUNK - Earn a four star rank or better on the Island map.
Jack Krauser - Earn a four star rank or better on the Castle map.
Unlock the following costumes by performing the corresponding tasks:
COSTUME - HOW TO UNLOCK
Ashley (armor) - Complete Separate Ways.
Ashley (pop star) - Complete the game
Leon (gangster) - Complete Separate Ways.
Leon (Resident Evil 2) - Complete the game.
Unlock the following bonuses by performing the corresponding tasks:
BONUS - HOW TO UNLOCK
Alternate outfit for Leon, Ashley, Ada - Beat the game once
Chicago Typewriter (Main game) - Beat Separate Ways
Handcannon - Obtain five stars for each level in the Mercenaries
Infinite Rocket Launcher - Beat the game once
P.R.L. 412 - Beat the game on Professional
Matilda (New Game+ Only) - Beat the Main Game
Professional Difficulty - Beat the game once
Separate Ways - Beat the game once
Ditman speed glitch:
After equipping the Striker shotgun, aim the shotgun and immediately go into your inventory before the laser sight of the Striker has a chance to show up on screen. Equip any other weapon and exit out of your inventory. If done correctly, Leon will now run, climb ladders, knife, and shoot twice as fast. The glitch is disabled after a cutscene, an area transition, taking damage, opening doors, doing a quick-time event, or dodging an explosion.
It Begins With a Ring - Ring the mysterious bell. What happens after that, is up to you.
Do Not Shoot the Water! - Summon the master of the lake. Don't rock the boat.
A Rock and a Hard Place - Outmaneuver the rampaging beast, El Gigante.
Secure the Ballistics - Rescue the president's daughter, Ashley. Afterwards, the real fun begins.
A Bloodline Severed - Defeat the village chief in battle.
The Castellan Falls - Defeat Salazar, and make your escape from the castle.
The Ties That Bind - Defeat Krauser, your former partner, in battle.
We're Going Home - Defeat Saddler in battle, and escape from the nightmare.
A Terrifying Assassin - Turn the tables on Verdugo, the right hand of Salazar.
A Heart of Steel - Clear the game on the highest difficulty.
What Are They Worth? - Acquire all of the bottle caps in the game.
The S Stands for Stylish!! - Acquire all of the costumes in the game.