Ninja Gaiden Sigma is a remake for PlayStation 3 consoles of the Ninja Gaiden game created by Tecmo and published by Ubisoft. However, Tomonobu Itagaki, the designer of the original game was not directly involved in the creation of Ninja Gaiden Sigma and this steered up some disputes. Below you will find a collection of cheat codes and unlockables for Ninja Gaiden Sigma.

Cheats:

Bonus missions
Press Up, Down, Left, Down, Right, Up, Square at the Mission mode screen to unlock five bonus missions.

Unlockables:

Mission mode
Successfully complete Story mode under the Normal difficulty setting.

Ashtar Ryu costume
Successfully complete Story mode under the Hard difficulty setting.

Classic Ryuken costume
Successfully complete Story mode under the Normal difficulty setting.

Ninja Dog mode
Intentionally die three times.

Hard mode
Successfully complete the game under the Normal difficulty setting.

Very Hard mode
Successfully complete the game under the Hard difficulty setting.

Master Ninja mode
Successfully complete the game under the Very Hard difficulty setting.

Golden Scarab bonuses
Collect the indicated number of Scarabs:

Armlet of Benediction: 30 Golden Scarabs
Armlet of Celerity: 25 Golden Scarabs
Armlet of Fortune: 40 Golden Scarabs
Armlet of Potency: 5 Golden Scarabs
Dabilahro: 20 Golden Scarabs
Great Spirit Elixir: 35 Golden Scarabs
Jewel of the Demon Seal: 45 Golden Scarabs
Life of Gods: 1 Golden Scarab
Lives of the Thousand Gods: 10 Golden Scarabs
Plasma Saber MkII: 50 Golden Scarabs
Spirit of the Devils: 15 Golden Scarabs