Alternate Ayame Costume  -  At the item select screen press Left, Left, Down, Down, Square, Square, Triangle, Circle. Then, the armor icon will automatically be selected. Now begin game and play as Ayame and select her third costume. 

Bear Mode  -  Pick a level with a Bear in it like the 3rd level. Then put in debug mode. Put a bear in the level (Layout Enemy, Add, Kuma, Pad1).Then use Go in the Layout Enemy option. Run far enough for the bear to appear again. Then pick the bear's camera (Layout Enemy, Select Camera Owner, pick the last camera, it should be his.) Then when you have his camera charge Item and pick the Enemy Clothes it should be on the last page. Use it and your ninja should be running around on all fours. This trick works with other enemies too. 

Bonus Weapons - Japanese Version  -  At the weapon selection screen, hold R1 or L2 and press Up, Up, Down, Down, Left, Right, Left, Right, Square, Triangle. 

Debug Mode  -  Pause the game and hold L1 and R2. Next press Up, Triangle, Down, X, Left, Square, Right, Circle, L1, R1, L2, R2.The screen shudders. Then freezes. Hit pause to resume playing, then press L2 + R2 together during game play. 

Healing - American Version  -  To restore your health, pause the game and press Left, Left, Down, Down, Square, Square, Triangle, Square. You will know that you entered the code correctly when you hear a ninja say "HUH"! 

Healing - Japanese Version  -  To heal, pause the game then press Up, Up, Down, Down, Left, Right, Left, Right, Square, Triangle. A shout will confirm the code. 

Increase Number Of Items  -  At the item select screen hold L2 then press LEFT, LEFT, DOWN, DOWN, SQUARE, SQUARE, TRIANGLE, X. 

Increased Carrying Capacity - American Version  -  At the item selection screen HOLD L1, then press LEFT, LEFT, DOWN, DOWN, SQUARE, SQUARE, TRIANGLE, SQUARE. 

Increased Carrying Capacity - Japanese Version  -  To hold up to 99 weapons, go to the weapon selection screen, hold L1 and press Up, Up, Down, Down, left, Right, Left, Right, Square, Triangle. 

Japanese Dialogue (PAL Version)  -  On the mission select screen, hold L1 and press: Square, Square, Triangle, Triangle, Right, Right, Up, Down. When the cinematics come up, the characters will speak Japanese. To turn the Japanese dialogue off, go to the mission select screen and do the cheat again. NOTE: This may not work on every stage. 

Japanese Dialogue on stages 3, 6, 9, 10  -  This cheat only works on stages 3, 6, 9, 10. During the cinematics the characters will speak in Japanese instead of English. At the Stage Select screen, HOLD L1 then press Left, Left, Down, Down, Square, Square, Triangle, then Circle. You will here a confirmation that the code worked. Then begin one of the stages above. 

Layout Select (PAL Version)  -  On the mission select screen, hold L2 and press: Square, Square, Triangle, Triangle, Right, Right, Up, Left. This will allow you to choose which Layout (A, B or C) to play. 

Level Layout Select  -  Here is a code that allows you to select the layout A, B, or C of the level you are going to play. To activate this code, enter the following sequence at the level select screen: While holding R1, press left, left, down, down, square, square, triangle, X. 

Level Select - American Version  -  Select a character, then hold R2 and press LEFT, LEFT, DOWN, DOWN, SQUARE, SQUARE, Triangle, Square at the next screen. 

Level Select - Japanese Version  -  On the stage select screen (levels appears when you've beet them) hold R2 and press Up, Up, Down, Down, Left, Right, Left, Right, Square, Triangle. 

Level Select - PAL Version  -  On the Mission select screen, hold R1 and press: Square, Square, Triangle, Triangle, Right, Right, up, Right. This will unlock all 10 missions. 

Los of free items...the hard way  -  Go to training and try to get grand master, then Lord Gohda will give you one item each time you get grand master. 

Lots of free items  -  At the item selection screen HOLD R1, then press LEFT, LEFT, DOWN, DOWN, SQUARE, SQUARE, TRIANGLE, CIRCLE. You can also HOLD R1 then press SQUARE, SQUARE, TRIANGLE, TRIANGLE, RIGHT, RIGHT, UP, LEFT, or HOLD L2 then press SQUARE, SQUARE, TRIANGLE, TRIANGLE, RIGHT, RIGHT, UP, RIGHT. 

Play as Onikage 

First enter the debug code, access the debug screen, hit "charge item", then "kawarimi", then hit FULL (this item is the "resurrection leaf", Ayame or Rikymaru will have this item so that if they are atacked by an enemy the won't kill them and the game will not end if they are killed). You will be able to play as Onikage in the lever witch he appears: 3,6,9 and 10. Enter the debug screen again, choose "layout enemy", then "add", then choose "NINJA", then "pad 1". Then go to the debug screen again, "layout enemy", then "go". Walk in any direction far enough to let the normal play screen reapear Onikage. Now enter the debug screen again, hit "layout enemy", then "select camera owner", then hit the last number the apears on the second page of the "camera owner screen" (except on level 10 witch is number 23 because Onikage is not the final boss of this level). Now you will be able to play as Onikage and see him as if you were playing with Rikymaru or Ayame. You can also add any iten to Onikage, except the "grapling hook", but you can use the item "the world" instead, witch will move Onikage to the spot you are aming at. This code can also be use for Lord Meyo (number 24 on level 10 only) or any other enemy that you know the "camera owner" number.

IMPORTANT!!!: You must get the number of the enemy that you want to use just right or the camera will go to another place of the level and you will have to reappear the enemy that you were using and the items again. Have fun kicking some butt with Onikage! 

Play as anyone in the entire game  -  First do the play as Onikage code only you don't have to pick Onikage. Just pick any character and hit go. Then run away, when you come back your character will do everything you say. Position your character to be looking at you, jump and hit square in the air and it will hit you. Then pick select camera owner and then pick the last number and you're set.
Note: this code is glitchy so don't try to use all different kinds of weapons or the game will freeze 

Two Players  -  First do the debug mode. Then choose enemy option. Choose any enemy (a level 2 ninja would be the best). Then choose Pad-2. Then run away from P2. When you see a question mark (near your life bar) run back to P2. Now Player 2 can move the enemy you have selected for him/her. Try level 4 (The checkpoint) at the bridge so you and P2 can fight and knock each other off. Note:  If leave Player 2 he/she will disappear.   Note:  If P2 fall in deep water he/she will drown.