Unlock Ninja Dog
Die three times consecutively in Chapter 1., then accept the choices given to you.
Unlock Hard
Complete the game on Ninja Dog or Normal difficulty, or have a save file on your hard drive where you completed the original Ninja Gaiden on Xbox.
Unlock Very Hard
Complete the game on Hard difficulty, or have a save file with the clear data of the Hurricane Pack 2
Unlock Master Ninja
Complete the game on Very Hard.
Unlock Movie Theater
Complete the game with any difficulty level.
Unlock Arcade Ninja Gaiden
Complete the game on Ninja Dog or Normal difficulty with the "Ninja Gaiden Arcade" item, or complete the game on Hard.
Unlock Coming Attractions
Play the game for over 1 hour.
Unlock Ayane-themed Start Screen
Load a Ninja Dog save file, and reset the game(start+back)
Unlock all music in "Sound Test"
Complete the game on any difficulty, and you will be able to listen to the game's music from the options menu.
Unlock Mission Mode
Beat the game on any difficulty
More Missions in Mission Mode
Beat five missions to unlock five more
Play Missions on Multiple Difficulties
Beat a mission, and you unlock Hard for that mission. Beat Hard to unlock Very Hard, and Very Hard to unlock Master Ninja. Ninja Dog is not available.
Play Japanese version of Arcade Ninja Gaiden
After unlocking the arcade Ninja Gaiden at the main menu, change both text and speech to Japanese, and you will be able to play the arcade Ninja Gaiden in Japanese.
Kill Rachel and Ayane
In Chapter 2 when Ryu finds Ayane wounded in the 2nd floor of Murasma's shop, shoot her with the bow she gives you. In Chapter 13 when you warp to the grassy plane, you can use the bow to nail Rachel in the distance, killing her. Both of these actions lead to immediate Game Overs, so save before hand.
Scarab Rewards In Ninja Dog (Easy) Mode
Life Of The Gods - 1 Scarab
Armlet Of Potency - 5 Scarabs
Life Of A Thousand Gods - 10 Scarabs
Spirit Of The Devils -15 Scarabs
Dabilahro - 20 Scarabs
Armlet Of Celerity - 25 Scarabs
Armlet Of Benediction - 30 Scarabs
Great Sprit Elixer - 35 Scarabs
Armlet Of Fortune - 40 Scarabs
Jewel of The Demon Seal - 45 Scarabs
Arcade Ninja Gaiden - 50 Scarabs
Kill Rachel and Ayane
In Chapter 2 when Ryu finds Ayane wounded in the 2nd floor of Murasma's shop, shoot her with the bow she gives you. In Chapter 13 when you warp to the grassy plane, you can use the bow to nail Rachel in the distance, killing her. Both of these actions lead to immediate Game Overs, so save before hand.
Play Japanese version of Arcade Ninja Gaiden
After unlocking the arcade Ninja Gaiden at the main menu, change both text and speech to Japanese, and you will be able to play the arcade Ninja Gaiden in Japanese.
