During play, pause the game, hold L1+L2+R1+R2 and enter the following codes:

Infinite Missile Weapons: Sguare, square, down, circle.
Play as Faramir: x, x, triangle, triangle.
Aragorn 1000 xp: Up, square, triangle, x.
Aragorn level 8 skills: Up, square, triangle, up.
Gandalf 1000 xp: Circle, triangle, up, down
Gandalf level 8 skills: Circle, square, down, down.
Frodo 1000 xp: Up, triangle up, down.
Frodo level 8 skills: Circle, circle, down, down.
Sam 1000 xp: Triangle, x, down, x.
Sam level 8 skills: Circle, circle, triangle, triangle.
Legolas 1000 xp: x, triangle, up, x.
Legolas level 8 skills: Square, up, up, down.
Gimli 1000 xp: Circle, circle, triangle, x.
Gimli level 8 skills: x, circle, down, square.

The following codes will only work after you have beaten the game once.

During play, pause the game, hold L1 + L2 + R1 + R2 and enter the following
codes:

Play as Frodo: Circle, Square, Square, X.
Play as Merry: X, Down, Down, X.
Play as Pippin: Triangle, Circle, Square, Down.
Invincibility: Square, Circle, Square, Up.
Full Health: Square, Square, Circle, Circle.
Perfect Mode: Circle, Down, Triangle, X.
All Attack Upgrades: Up, Down, Triangle, Square.
Always Devastating: Triangle, Up, Triangle, Down.
Target: Down, Circle, Up, Square.
Aragorn 4-hit Combo: Up, Square, Triangle, Down.
Gandalf 4-hit Combo: Down, Triangle, Up, Circle.
Legolas 4-hit Combo: X, Circle, Triangle, Square.
Gimli 4-hit Combo: Triangle, Square, Up, X.
Frodo 4-hit Combo: Circle, Square, Square X.
Merry 4-hit Combo: Triangle, X, Square, Square.
Pippin 4-hit Combo: X, X, Down, Circle.
Sam 4-hit Combo: Up, Down, Triangle, Triangle.
Developer Interviews: Beat the game once.