O
 O.D.T.

Full Energy
Pause the game and press Left, Right, Left, Right, Square.
Full Ammo
Pause the game and press Left, Right, Up, Down, Circle, Square.
Full Mana
Pause the game and press Left, Right, Left, Right, Circle.
Upgrade Magic
Pause gameplay and press Down, Triangle, Select, L1, R1, Select.
Upgrade Weapon Level
Pause gameplay and press R1, L1, R2, L2, Left, Right, Up, Down.
Full Experience
Pause gameplay and press Circle, Triangle, L1, L2, R1, Select.
Play as Sophia
At the Main Menu, press L1, L2, R2, R1.
Play as Karma
At the Main Menu, press R1, R2, L2, L1.

 Oddworld 2: Abe's Exoddus

Path Skip
During gameplay, hold R1 and press Circle, Circle, X, X, Square, Square.
Level Select
At the Main Menu, hold R1 and press Down, Up, Left, Right, Triangle, Square, Circle, Triangle, Square, Circle, Down, Up, Left, Right.
View FMV Sequences
At the Main Menu, hold R1 and press Up, Down, Left, Right, Square, Circle, Triangle, Circle, Square, Circle, Up, Down, Left, Right.
Invincibility
While playing a game, hold R1 and press Circle, Triangle, Square, X, Down, Down, Down, Circle, Triangle, Square, X.

 Oddworld: Abe's Odyssey

Level Passwords
Go to the Options screen and hold R1, and then press Down, Right, Left, Right, Square, Circle, Square, Triangle, Circle, Square, Right, Left
Movie Player
At the Title screen, where you see Abe, hold R1, and then press Up, Left, Right, Square, Circle, Triangle, Square, Right, Left, Up, Right. Abe will say "Ok" and take you to the Movie Player.
Green Fart
While playing a game, hold R1, and then press Up, Left, Right, Square, Circle, X
Voice Puzzle
While playing a game hold R1, and then press Triangle, Up, Left, Circle, Left, X, Down, Square, Right.

 Off-World Interceptor Extreme

Collect Extra Cash
First, you must select options on the Main Menu Screen. Once you are in options, press Square, X, Circle, six times in a row, then hit L1. Having entered the code correctly, you will notice that the amount of cash you have has increased.

 Olympic Summer Games

Bonus Cycling Event
Enter NEW as a name and select France as a country. Then, hold Select and press L2, R2, L1, R1, Up, Up, Down, Down.

 Omega Boost

 One

Various Cheats
Enter the following at the password screen:
Password
Effect
Maxpower
All Weapons
Heavyfeet
Level Select
heybuddy
Debug Mode
Clean Pause Screen
THEPRESS
Level Passwords
2 -- DIYGIXRA
3 -- KCSVJTJB
4 -- RWLKLPBC
5 -- YQFZMLTC
6 -- FLZNOHLD

 Option Tuning Car Battle

W-Wagon Car
Select Arcade Mode, then choose car type N33 or Mines. Now press Start.
Supatazen Car
Select Arcade Mode, then choose car type N33 or Mines. Now press Start.
One Million Dollars
Enter "Dai" as a name.

 Option Tuning Car Battle 2

View Ending Sequence
At the Title screen, press R1, Circle, Triangle, Right on Controller Two.
All Cars
First enable the code above, View Ending Sequence. Then select Arcade Mode and press R1, Circle, Triangle, Right on Controller Two.

 Orge Battle

Big Battle
Start a new game, and when you get to the Enter Name screen, enter the name FIRESEAL.

 Overblood

 Overblood 2

Super Jump
Hold X, then press Square and a direction on the D-Pad.
Survive Falls
Display the item menu while falling from a high location. Equip a weapon, then remove it.

 Overboard

Passwords
1-2: Ship, Skull, Fish, Anchor, Ship, Anchor
1-3: Ship, Anchor, Skull, Ship, Anchor, Fish
1-4: Skull, Ship, Fish, Anchor, Anchor, Ship
2-1: Fish, Fish, Anchor, Ship, Skull, Anchor
2-2: Skull, Anchor, Anchor, Fish, Anchor, Ship
2-3: Fish, Anchor, Ship, Ship, Ship, Skull
2-4: Anchor, Fish, Ship, Skull, Skull, Fish
3-1: Ship, Skull, Skull, Fish, Anchor, Skull
3-2: Fish, Skull, Anchor, Fish, Skull, Fish
3-3: Fish, Fish, Ship, Skull, Fish, Ship
3-4: Ship, Anchor, Ship, Fish, Anchor, Fish
4-1: Skull, Skull, Anchor, Ship, Fish, Fish
4-2: Ship, Anchor, Skull, Fish, Fish, Anchor
4-3: Skull, Ship, Skull, Skull, Fish, Ship
4-4: Ship, Fish, Ship, Fish, Ship, Anchor
5-1: Anchor, Ship, Fish, Skull, Fish, Ship
5-2: Fish, Ship, Anchor, Skull, Ship, Fish
5-3: Ship, Fish, Skull, Anchor, Anchor, Skull
5-4: Skull, Ship, Anchor, Fish, Ship, Skull