Successfully complete Separate Ways mode to unlock Ashley's armored knight and Leon's suit.
Successfully complete the game on the Professional difficulty setting to unlock the PRL 412 weapon. Successfully complete the game to unlock Professional mode, the 'Extras' menu (with 'Bonus', 'Separate Ways', 'Assignment Ada', 'Mercenaries', and 'Movie Browser' options), 'Wii Edition credits' option (in the 'Bonus' menu), Infinite Rocket Launcher, Matilda, and alternate costumes for Ashley, Leon, and Ada. Note: This game is also titled Biohazard 4: Wii Edition.