Blade II
Level Select
At the main menu, hold L1 and press Down, Up, Left, Left, O, Right, Down, Square.
Infinite Health
Pause the game, then hold L1 and press Triangle, Square, Triangle, Square, Triangle, O, Triangle, O.
All Weapons
At the main menu, hold L1 and press Square, O, Down, Left, O, O, Triangle.
Infinite Ammo
Pause the game, then hold L1 and press Left, O, Right, Square, Up, Triangle, Down, X.
Daywalker Difficulty Setting
At the main menu, hold L1 and press Left, O, Up, Down, Square, O, X.
Infinite Rage
Pause the game, then hold L1 and press Left, Down, Left, Down, Right, Up, Right, Up.
The database at Game Oak contains more information regarding Blade II for Sony PlayStation 2.