RESIDENT EVIL 4 UNLOCKABLES
Completion bonuses
After finishing the game you will unlock the Assignment Ada and Mercenaries-mini-games; the Professional difficulty setting; the Leon's Raccoon City Police Department costume, Ashley's pop star costume, and Ada's black costume; and the Mathilda handgun and Infinite Rocket Launcher for purchase (for 1 million Pesetas).
Mercenaries mini-game Bonus characters Ada Wong
Get a four star rank in Pueblo.
Mercenaries mini-game Bonus characters Albert Wesker
Get a four star rank in Waterworld.
Mercenaries mini-game Bonus characters Hunk
Get a four star rank in Island Commando.
Mercenaries mini-game Bonus characters Jack Krauser
Get a four star rank in Castle.
Mercenaries mini-game Handcannon
Get a five star rank with all mercenaries to unlock the Handcannon weapon. To get unlimited ammunition for it, fully upgrade all of the Handcannon's options.
Chicago typewriter
Finish the Assignment Ada mini-game to unlock the Chicago Typewriter (Tommy gun with unlimited ammunition) for purchase (for 1 million Pesetas).
Game trailers
Remain idle at the title screen. Eventually two trailers will begin playing and begin to cycle.
Extra scene
When Leon is being choked, he will be told that he has the same blood. Leave the room, then return. You will be choked again by same person, only this time Ada comes to the rescue.