Ninja Gaiden Sigma

Ninja Gaiden Sigma
North American cover art
Developer(s)	Team Ninja
Publisher(s)	Tecmo EU: Eidos Interactive
Designer(s)	Yosuke Hayashi
Series	Ninja Gaiden
Platform(s)	PlayStation 3, PlayStation Vita
Release date(s)	PlayStation 3 JP: June 14, 2007 NA: July 3, 2007 EU: July 6, 2007 AU: July 13, 2007 PlayStation Vita NA: February 22, 2012 EU: February 22, 2012 JP: February 23, 2012
Genre(s)	Action-adventure, hack and slash
Mode(s)	Single-player

Ninja Gaiden Sigma, stylized as Ninja Gaiden Σ, is an action-adventure game developed by Team Ninja for the PlayStation 3. It is an enhanced port of Ninja Gaiden, originally released on Xbox in 2004, and is the second expansion to the game after Ninja Gaiden Black. The game was released in the summer of 2007 to very positive reviews. In 2012, a port for the PlayStation Vita, titled Ninja Gaiden Sigma Plus was released on the same day the console launched in Europe and North America.

The gameplay for Sigma is very similar to the original version, albeit with some modifications made to the game. Like the original version, the player's movements and combat system are directed using the console gamepad, which comprises the left thumbstick, two attack buttons, and a block button. The game features a large selection of weapons for Ryu to wield each with advantages and disadvantages that affect the way the player approaches combat. A new addition to Ryu's arsenal is a pair of dual-wield swords, Dragon's Claw and Tiger's Fang. It also provides Ryu with magical spells in the form of ninpo, which allows him to inflict heavy damage on enemies while potentially avoiding damage himself. By shaking the Sixaxis controller, players are able to increase the power of their ninpo spells.Rachel, a non-playable character in the 2004 game, became playable in three new chapters, featuring the new bosses, Gamov and Alterator. Some of the design elements of the old levels was also changed and several new enemy types were introduced.

In addition to the narrative Story Mode, Sigma included a gameplay variation called Mission Mode. Focused on action rather than character development, this provides combat-based missions set mainly in small areas. In both Story and Mission modes, game scoring is based on the player's speed in clearing encounters, the number of kills achieved, the number of unused ninpos remaining at the end, and the amount of cash collected. Players can compare their scores on online ranking boards. In addition, players have the option to customize the appearance of player characters, with selectable costumes for Ryu and hairstyles for Rachel.