Start a game on Normal Mode. Now don't take ANY items. When you reach the front yard of the Police Station, run down the stairs to find Brad Vickers in zombie form. Kill him, then check his body for the Special Key. Now continue through the game to the Dark Room. Unlock the locker in the corner. Claire has 1 extra costume and 1 extra weapon, Leon has 2 extra costumes.
Rocket Launcher w/ Infinite Ammo
Complete either character's A scenario with an A or B rank in under 2 1/2 hours.
Gatling Gun w/ Infinite Ammo
Complete either character's B scenario with an A or B rank in under 2 1/2 hours.
Sub Machine Gun w/ Infinite Ammo
Complete either character's B scenario with an A or B rank in under 3 hours.
Check the desk in front of the S.T.A.R.S. logo in the S.T.A.R.S. Office 49 times for Film. When developed, it shows Rebecca Chambers in her RPD basketball uniform.
Complete the A scenario of one character and the B scenario of the other with an "A" rank on each to unlock the HUNK mini-game. HUNK is one of the soldiers sent by Umbrella to recover the G-virus.
Complete the A scenario of one character three times and the B scenario of the other three times with an "A" rank on each to unlock the TOFU mini-game. It's the same as the HUNK Mini-game, except you're a chunk of Tofu armed with only a knife.
Extreme Battle Mode
Complete either character's A scenario, then complete the other character's B scenario.
Play as Ada Wong in Extreme Battle Mode
Complete Level 1 of Extreme Battle Mode.
Play as Chris Redfield in Extreme Battle Mode
Complete Level 2 of Extreme Battle Mode.
At the Status Screen, press Up, Up, Down, Down, Left, Right, Left, Right, Aim.
Unlock All Unlockable Cheats
In Windows, open the Registry Editor. Navigate yourself to "HKEY_LOCAL_MACHINE\SOFTWARE\CAPCOM\RESIDENT EVIL2\" and enter the value "8".