Set in the futuristic version of the 21st century, players control Ryu Hayabusa, a master ninja, in his quest to recover a stolen sword and avenge the slaughter of his clan.

Making use of the Xbox's internet connectivity, Tecmo promoted Ninja Gaiden with a series of international online contests; record-breaking numbers of players competed for places in the live final held at the 2004 Tokyo Game Show.

Ninja Gaiden was critically acclaimed and sold 362,441 copies in North America in the first month of release; however, Japanese sales were poor.

Viewed from a third person over-the-shoulder perspective, in typical action-adventure fashion Ryu starts the game with basic, low-level abilities and weapons that can be upgraded as he progresses, by discovering or buying items.

[4] Access to these regions are obtained by fighting enemies, finding keys, or solving puzzles, inspired by the mechanics of The Legend of Zelda video games.

[8][9][10] Eric Williams, the designer of the God of War combat engine, explained that Ninja Gaiden prohibits players from stopping or changing attacks in mid-stroke.

Williams said that, compared to those two games, the combat system in Ninja Gaiden was harder to master; however, it lets players fight their computer controlled foes on equal terms.

[8] Ninja Gaiden features a large selection of weapons for Ryu to wield, each with advantages and disadvantages that affect the way the player approaches combat.

[20] Located mainly in Japan and the fictional Western Asian nation of the Vigoor Empire, the game draws on Heian period structures for its Japanese locales—a ninja fortress and village set in the mountains.

[13] European-style buildings and the monastery in Tairon exhibits Gothic influences with a vaulted hall, pointed arches, and large stained glass windows.

A hidden underground level features statues with the heads of cats, walls covered with carvings, hieroglyphics, Aztec pyramid and a labyrinth.

[26][27] Ninja Gaiden provides a backstory to Ryu's appearance and character as seen in the Dead or Alive series, being set two years before the first DOA game.

The relationship between the sisters and the Greater Fiend Doku, who cursed them, serves as a plot device to drive the game forward,[29] with Rachel occasionally needing to be rescued by Ryu.

Muramasa also gives quests and relates back-stories and other crucial information; for example, he tells Ryu how he can obtain the item required to upgrade his Dragon Sword to its full potential.

Fighting his way back to his village, Ryu encounters Doku, who has killed the Hayabusa shrine maiden Kureha and has taken the Dark Dragon Blade.

Ryu is cut down by Doku with the stolen Blade, but he is brought back to life as a "soldier of revenge" by a falcon, the spiritual animal of the Hayabusa clan.

Seeking vengeance for the death of his childhood friend, Ryu learns from Murai that the raiders are from the Vigoor Empire, a mysterious clan that takes refuge in the city of Tairon.

While Rachel mourns the death of Alma, Ryu storms the Imperial Palace and faces the Holy Vigoor Emperor in a fiery volcanic pit.

The Disciple reveals himself to be Murai and admits that the raid on Hayabusa village was part of his plan to restore the Blade's evil power, using souls harvested by Ryu.

[38] However, for retail reasons Tecmo wanted to retain a link with the previous games, which had many adherents in the West,[26] so Itagaki was asked to rethink his ideas to target the foreign market.

[39] In 2004, Tecmo released a demo disc of Ninja Gaiden in Japan, bundled with the February 26 issue of Famitsu Xbox magazine.

Since this had the potential to place Ninja Gaiden in Germany's "List of Media Harmful to Young People", which would have meant that shops could neither advertise the game nor sell it unless by request to customers of 18 years or older,[50] Tecmo censored the European PAL version to obtain a USK rating.

[64][65] Six of the highest scoring players from Europe and North America won bokkens bearing Itagaki's signature,[64][66] and five regional winners were selected to proceed to the final.

Although Itagaki deemed Black to be the final version of Ninja Gaiden,[58] Tecmo subsequently ported the game to the PlayStation 3 as Sigma.

Focused on action rather than character development, this provides combat-based missions set mainly in small areas, where the player's goal is to "destroy all enemies".

[85] Hence he ensured that those players selecting Ninja Dog would be subjected to gentle mockery by the game—players on this difficulty setting receive colored ribbons as accessories, and Ayane treats Ryu as an inferior.

Although the gaming site 1UP.com called the updated graphics "a gorgeous reworking of the modern ninja classic,"[107] Pro-G said that they were average by next-generation standards and showed occasional "tearing, jagged edges, and mismatched collision between bloodstains and walls.

IGN warned that gamers with lesser skills might not "get as much out of this game as others due to [its] incredible difficulty",[115] and Edge commented that "Tecmo's refusal to extend any kind of handhold to less dedicated players is simply a failure of design, not a badge of hardcore honour", and "it's impossible to believe they couldn't have found a way to increase the accessibility of the game without undermining the gloriously intractable nature of the challenges it contains.

Ninja Gaiden, in his opinion, strikes the correct balance between challenge and reward; completion brings "a sort of exhausted exhilaration, like finally reaching the end of War and Peace.

"[142] From a technical point of view, critics regarded Ninja Gaiden and Black as the best of the available Xbox software at the time; the console hardware had been pushed to its limits without showing significant drops in performance.