Highlight Shang Tsung (for player one) or Quan Chi (for player two) at the character selection screen, then hold Up + Start.
Alternate costumes
After the appropriate costumes are unlocked in the Krypt, press Start at the character selection screen to access the new costume.
Versus mode skill select
Press L2 before either player chooses a character.
Background FMV sequence
Press Triangle at the main menu and a movie screen will appear. It shows the story leading up to the start of the game.
Fatalities
Fatalities may be done from anywhere on screen. Note: 1, 2, 3, 4 represent the attack buttons. Note: Press the stance change button at the "Finish Him/Her" screen to change into your fatality stance, or you will have to figure out the distance range.
Bo Rai Cho (Belly Flop):
Press Away, Away, Away, Down, 4
Johnny Cage (Brain Ripper):
Press Away, Toward, Toward, Down, 2
Open the FN Krypt first to get 1800 of the 3300 that is needed, before opening the XG Krypt to unlock Raiden.
Monk movement
Remain idle long enough during Konquest mode and the "monk" will turn around and shrug his shoulders at you.
Play As Blaze Or Mokap
Open coffins PN and YP in the Krypt. Clear quest mode with all the regular and hidden characters. Once that's done, hold DOWN while selecting Raiden to access Blaze. Hold DOWN while selecting Cyrax to select Mokap.
Costumes
Bo' Rai Cho in vest - PH 1200 Onyx
Cyrax as human - ZW 1485 Sapphire
Drahmin as mummy - SW 1152 Jade
Frost unmasked - UB 1261 Gold
Hsu Hao w/out hat - Qx 1518 Jade
Jax in street clothes - ZM 1410 Ruby
Johnny Cage in tuxedo - DK 1460 Ruby
Kano MK1 clothes - BD 1520 Sapphire
Kenshi w/ torn clothes - YM 1435 Platinum
Kitana costume - BQ 1327 Gold
Kung Lao MK1 Clothes - YJ 1280 Ruby
Li Mei in bekini - KX 1406 Sapphire
Mavado w/ Armor - RD 1455 Jade
Nitara Costuem - AR 2206 Jade
Quan Chi MK4 Clothes - AA 1556 gold
Raiden as samurai - JR 1685 Ruby
Reptile w/ skull helmet - XO 1736 Sapphire
Scorpion w/ flaming skull - UH 1660 Jade
Shang Tsung MK2 Clothes - ML 170 Gold
Sonya Blade military fatigues - SH 1834 Ruby
Sub-Zero w/ mask - YA 1999 Sapphire
Stage Select and Handicaps in VS mode
When in VS mode, do the following:
Effect - Code
Set a handicap on yourself - Press L2
Choose what stage you are going to fight in - Press R1
Attack Early
At the loading screen before the fight, unplug your controller, then plug it back in. You will now be able to move around and attack before it says "Fight". This is better for taking care of harder enemies, by getting a head start in the match.