At the mission selection screen, press L1, R1, L2, R2, Right, Square, L3, R3.
At the title screen, press L1, Up, R1, Down, L2, Right, R2, Left. Alternatively, successfully complete the game with all three characters.
At the title screen, press Up, Down, Right, Left, X(3). The demo level that was available on the free demo disc will now be unlocked.
At the versus or coop level selection screen, press L1, R1, L2, R2, Right, Square, L3, R3. -From: firstname.lastname@example.org
At the mission selection screen, press R3, L3, R2, L2, R1, L1.
At the title screen, press L1, R2, L2, R1, Right, Left, L3, R3.
At the item selection screen, hold L1 + R1 and press Up, Square(2), Left, Square(2), Down, Square(2), Right, Square(2).
At the item selection screen, hold L2 + R2 and press Square(3), Up, Left, Down, Right.
At the item selection screen, hold L1 + L2 + R1 + R2 and press Square(3), Up, Left, Down, Right, Square, Up, Right, Down, Left. Although you can only still carry six different items, you can have an unlimited amount of those specific items.
Pause the game and press Up, Down, Right, Left, Square(3).
Pause the game, then hold L1 + L2 and press Up(2), Down(2). Release L1 + L2 and press Square(2), R1, R2.
Pause the game and press Right(2), Left(2) on controller two.
Pause the game, then hold L1 + R1 and press Right(2), Left(2) on controller two to add 100 points to your score.
At the title screen, hold L1 + R2 and press Down, Square, Up, Square, Right, Square, Left, Square. Alternatively, successfully complete layout 1 with a "Grand Master" rank. Select the "B-side dialogue" option at the "Sound" menu to play the game with joke and outtake-style dialogue. -From: email@example.com
Successfully complete the game with Rikimaru and Ayame to unlock Tesshu.
To perform a secret attack with the various characters, spin the Left Analog-stick and tap Square. Note: This may require a few attempts.
This trick works better on high roof levels such as Rikimaru's first mission. If you have trouble anticipating when to perform a stealth kill, use a Poison Rice. Throw it in front of the guard and slice him before he eats it. Then, retrieve your rice and repeat the attack. You must be on a roof or cliff to do this best.
Run or walk up against an enemy's side or back and press Square (default) to stealth kill him. You can also stealth kill him in front, but you have to do this very quickly, before he notices you. Note: All stealth kills must be executed before the enemy notices you. Also, you can see different animations for each character depending on which side of the stealth kill is in view. Each character has a different stealth kill.
There are a few items that you can throw around a corner; Grenades, Poisoned Rice, Smoke Bombs, and Caltrops. Put your back to the wall using R1, move to the very end of the wall, and tap Triangle on the item you wish to throw around the corner. Your character will then take out the item and throw it. If it is a Smoke Bomb, the character will cough and you can move in for a stealth kill.
When playing as Rikimaru or Ayame, take the Fireworks item with you, and if desired, the Chameleon Spell to make this easier. Place the Fireworks close to your enemy. If he or she is unaware of your presence, he or she will die instantly. If you are spotted, you can lay the Fireworks and wait until the enemy is close enough. This will cause serious damage.
When you are falling long distances, hold R1. When you land, you will not fall over and have to wait for your character to get back up. This is useful when you are trying to jump on an enemy and miss.
Get a rank of Grand Master on a level to unlock new items. The item is different for every level.
Before you enter a level, bring about five or six Sticky Bombs with you. Save them until the Boss fight. Once you fight him, back up and use the Sticky Bombs. It should only take a few. This is the easy way to defeat Bosses, as the Sticky Bombs take off a lot of life and are unblockable.
When in a fight with two or more Demon Ninja, be very careful. If you are busy fighting one, the other can perform a stealth kill on you. Be sure to watch all Demon Ninja.