Cheat ----> Effect
L X A Y A X ---->Skip to Act 1 in Classical Ninja Gaiden 1
A X X R Y A ---->Skip to Act 2 in Classical Ninja Gaiden 1
X Y B R L X ---->Skip to Act 3 in Classical Ninja Gaiden 1
B R A B Y Y ---->Skip to Act 4 in Classical Ninja Gaiden 1
X A Y X L L ---->Skip to Act 5 in Classical Ninja Gaiden 1
R Y R L A X ---->Skip to Act 6 in Classical Ninja Gaiden 1
A A B X Y R ---->Skip to Act 1 in Classical Ninja Gaiden 2
X L R B B A ---->Skip to Act 2 in Classical Ninja Gaiden 2
L Y B A R R ---->Skip to Act 3 in Classical Ninja Gaiden 2
A L X Y Y B ---->Skip to Act 4 in Classical Ninja Gaiden 2
R A A B X L ---->Skip to Act 5 in Classical Ninja Gaiden 2
Y L R A Y R ---->Skip to Act 6 in Classical Ninja Gaiden 2
B B X Y A L ---->Skip to Act 7 in Classical Ninja Gaiden 2
B Y R L X A ---->Skip to Act 1 in Classical Ninja Gaiden 3
A R R Y A L ---->Skip to Act 2 in Classical Ninja Gaiden 3
L B R Y L Y ---->Skip to Act 3 in Classical Ninja Gaiden 3
R R B A Y X ---->Skip to Act 4 in Classical Ninja Gaiden 3
Y A B X R X ---->Skip to Act 5 in Classical Ninja Gaiden 3
B X X A X Y ---->Skip to Act 6 in Classical Ninja Gaiden 3
X R X Y Y L ---->Skip to Act 7 in Classical Ninja Gaiden 3

Hold the White button while selecting the 2nd trial mission ---->Wear the Dead or Alive costume
Hold the Black button while selecting the 2nd trial mission ---->Wear the Evil costume
At the main menu highlight New Game, hold Left Trigger + Right Trigger and press A ---->Original Blue Ninja Costume

Misc. Unlockables
Unlockable ---->How to Unlock
Life of the Gods ---->Give one scarab to Masamura
Sprit of the Devils ---->Give 10 scarabs to Masamura
Armlet of Benediction ---->Give 15 scarabs to Masamura
Dabilahro ---->Give 20 scarabs to Masamura
Armlet of Fortune ---->Give 30 scarabs to Masamura
Armlet of Tranquility ---->Give 40 scarabs to Masamura
Ninja Gaiden 1 ---->Give 50 scarabs to Masamura
Ninja Gaiden 2 ---->Obtain Ninja Gaiden 1, then shoot the clock face in Tairon near Muramasa's shop.
Ninja Gaiden 3 ---->Go to the peristyle passage in the Aquaducts, triangle jump back up to where you got the golden scarab on the top of the broken pillar.
Play Ninja Gaiden 1 from the main menu. ---->Beat the game with Ninja Gaiden 1 in your inventory.
Play Ninja Gaiden 2 from the main menu. ----> Beat the game with Ninja Gaiden 2 in your inventory.
Play Ninja Gaiden 3 from the main menu. ---->Beat the game with Ninja Gaiden 3 in your inventory.
Ninja of the Future outfit Complete the ---->game on normal or hard difficulty, then hold L and begin a new game
Plasma Saber ---->Complete the game on normal difficulty. Then, hold the left trigger when starting a new game
Very Hard difficulty ---->Complete the game on normal or hard difficulty.
Movie Gallery ---->Complete the game on normal or hard difficulty.
Unlock all Music in Sound Test ---->Finish the game once on Normal / Hard
Evil Ryu ---->Beat the game on the Very Hard difficulty
Dark Dragon Blade ---->Beat the game on any difficulty. Play again and visit Muramasa's shop in chapter 13.
Kitetsu ---->Defeat Doku at the end of Chapter 11. This sword will take health away slowly.
Unlabored Flawlessness ---->Purchase the Wooden Sword, then Upgrade the sword to its Maximum Level.
Windmill ---->Throwing Star Down the street from Han's Bar, in a narrow alleyway, you'll have to use the narrow blue-striped area to venture into the back corner to find the item
Plasma Saber Mk. 2 ---->Complete game on very hard mode

Unlockable How to Unlock
Jewel of Demon Seal 40 scarabs
Armlet of Benediction 35 scarabs
Armlet of the Sun 30 scarabs
Dabilahro 25 scarabs
Armlet of the Moon 20 scarabs
Vigoorian Flail 15 sacarbs
Armlet of Fortune 10 scarabs
Wooden Sword 5 scarabs
Armlet of Tranquility 45 scarabs
Dark Dragon Blade 50 scarabs