Beat the game once with Leon on any difficlty and any rank.
Begin game play then press Start to display the options screen. Select the "Button Config." option and highlight "Aim".
Before you use the custom parts on the VP70(Handgun), Desert Eagle(Magnum) or Shotgun use the remaing ammo in the clip/breech. When you use the custom parts to upgrade the gun it will automatically be fully loaded. This may seem like a small amount of ammo but can go a long way in the harder difficuties were ammo is rarer.
Complete both of either character's scenarios with an A rank to unlock it under the ''special'' option on the title screen.
To get new costumes in the game,start a new game with either character on Normal.
Do not pick anything up. (Anything)
When you get to the police station (don't go inside) you will see some stairs. Go down the stairs and there will be a zombie (who is Brad Vickers)
Kill him and he'll drop a ''Special Key''.
Use the key in the lockers in the dark room and there will be a screen that comes up that asks you if you want to switch costumes.
Say yes and you will have the ''new costumes''
Beat Extreme Battle Mode level 1 with any character.
Complete the game 6 times in a row, continuing from each game beaten. You must also unlock Hunk.
Beat the game on Normal Mode and get at least a ''B'' rank. It sould be in your chest when youstart over.
Just like the others versions of RE2, there's a secret film that can be found in the S.T.A.R.S. Office... Just have to search the desk that says ''it's trashed'' about 50 times.
To unlock the gattling gun, complete senario B with an A ranking without saving. This can be done simultaneously with unlocking the sub-machine gun. Also the rocket launcher obtained at the end does not decrease your rank.