Note: This game is also titled Biohazard 4: Wii Edition.
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.
Successfully complete the game on the Professional difficulty setting to unlock the PRL 412 weapon.
Successfully complete Separate Ways mode to unlock Ashley's armored knight and Leon's suit.
Successfully complete Assignment Ada and Separate Ways mode to unlock the Chicago Typewriter weapon for purchase for one million Pesetas.
Successfully complete Mercenaries mode with all characters with a five star rank to unlock the Handcannon weapon.
Get a four star or higher rank in the indicated Mercenaries mode level to unlock the corresponding character in Mercenaries mode:
- Ada Wong: Pueblo
- Albert Wesker: Waterworld
- Hunk: Island
- Jack Krauser: Castle
- Albert Wesker: Waterworld
When starting Mercenaries mode, play as Leon and go to the castle. It is much easier to get a good ranking because you can give the enemies a suplex, which almost always kills them in one hit. When you get Jack Krauser from the castle, you can then go to other areas, and it will make it much easier because of his arm.
There are two hidden cinematics accessible at the title screen. One can be accessed by remaining idle at the main menu until it starts. The other can be seen by pressing B on the Wii-mote at the main menu.
When the "Open" command appears by a door, tap A(2) to kick it open quickly. Doing this will also damage any enemies behind the door at the time you kick.
When you get to the church, shoot the bell. Every three times you shoot it, some villagers will appear. Kill them, and you will get anything from Pesetas to ammo and herbs. You can do this as many times as desired. This is effective if you have a lot of ammunition or the Chicago Typewriter.
To earn easy money while playing through the game again, carry an empty Handcannon. It costs no money to have, but you will pick up ammunition for it occasionally. This is worth more than any other type of ammo in the game. After collecting the ammunition, sell it to the merchant. Try using the Chicago Typewriter as your main gun while doing this.
Equip your handgun and aim the on-screen reticule at any torch or suspended light. Some times the reticule will turn red and deliver a slight jolt in the Wii-mote to indicate ammunition or a treasure that you can shoot from the light and retrieve. This is a slight advantage not available in previous versions of the game.
After you use the chief's false eye to open the door, walk up the hill until the truck comes at you. Shoot it and get back. Once it explodes, walk back up the hill, but go backwards. Keep going all the way to the castle and you will avoid facing the enemies that would normally appear.
Use the following trick to get through the town the first time. Rather than wasting ammunition and possibly dying, after you enter the house, run upstairs, kick out the ladder, and jump out. Then, go to the top of the tower in the corner of the town. The villagers will throw Molotov cocktails into the tower, but they cannot kill you. After awhile the villagers will go into the church. Once this happens, you can use Herbs or a First Aid Spray to restore your health. Since the villagers are gone, you can also check the houses for ammunition and PTAS.
If you find yourself surrounded by some parasites of Los Ganados or Los Illuminados and do not want to waste ammunition, quickly throw a flash grenade. Once it explodes, it should make the parasites explode, saving you ammunition.
After completing Separate Ways, you will unlock the armor suit for Ashley. Press Plus to make her wait, and run a short distance away. If an enemy tries to pick her up in the suit, they will fall down, as if they were shot in the leg. When this happens, run up and attack them with your knife until they get up. You can also use her to distract enemies and take them on one at a time.
Disconnect the Nunchuck when the game loads. When prompted to attach the Nunchuck, attach the Classic Controller instead. You can play classic style Laser Sight and all.
Remove the Nunchuck, and insert a GameCube controller into port one. You will now have a laser sight on your weapons and be able to use all of the GameCube's normal controls. Note: This is very helpful for sniping.
When fighting an El Gigante in its second form, take out your Killer 7 and shoot the parasite, or climb on its back and cut it. Either way, this saves health, ammunition, and a lot of frustration. Note: This is really only beneficial if you do not have one of the special weapons.
When fighting Krauser, it is easier to fight him with your knife instead of shooting him. If you shoot him, he will usually block and counter. To avoid this, slash him three or four times. He will then either kneel or flinch. When he does this, take out your strongest weapon and shoot him. If you are low on bullets, you can use grenades and mines. If you are playing Separate Ways, it is easier to use your knife the entire time.
Instead of shooting for their head, shoot them in the knee, then walk up to them. Instead "Kick", "Suplex" will appear. This will usually kill them instantly. This will not work if their head is armored.
If you find your rifle is empty, you can also defeat the Regenerator by shooting a mine into the spot around the parasite. If it is on its back, shoot out its legs with your handgun, then fire a mine into its back. If this does not work, find out where the parasite is on the Regenerator and try again.
When low on bullets, shoot the Regenerator in the leg with a powerful gun (for example, the magnum, rifle, or shotgun). It will fall to the ground. Run up to it, and attack it with the knife. Once you start attacking it, it will not be able to fight back or stand up. Keep attacking it until it dies. Note: Regenerators can attack you while they are on the ground, so you may get hit once. However, this technique saves much needed ammunition for the island and sewers. Make sure to have at least an Herb, and be prepared for an action command.
While you are in the giant crates, you can maneuver around U3. When you get to the gate, it will follow you. Run around and shoot it, bringing it closer to the explosive barrels. When you run out of barrels, fire either your shotgun or magnum.
To make Leon do a special trick with his hat, unlock the gangster costume and Chicago Typewriter. At any point in the game while in Leon's gangster costume, take out the Chicago Typewriter, aim, and shake the Wii-mote to reload. Leon will make a noise and move his hat. If you do this four times, he will throw his hat in the air and catch it on his head.
During the house scene, shortly after getting Ashley, shoot Luis five or six times. There will be an intermission where Luis is shot in the arm. He will then say "Adios, Leon!" and shoot him twice in the heart. Note: This will cause a game over.
After completing Separate Ways, select Special Outfit #2. During some of the intermission sequences (for example, the scene after the village), Leon will be in his standard clothes. After the scene, he will then be in the special outfit.
When you go into the room to fight Salzaar, look in front of Leon. The room looks just like when you fight him. However, when you step forward, there is an intermission sequence where Salazaar is standing on a platform that was not there before with one of his guards.