Ninja Gaiden

Ninja Gaiden is the North American version of the Famicom title Ninja Ryukenden (Legend of the Ninja Dragon Sword). It's also known as Shadow Warriors in Europe. In early 1988, in their advertisements from Nintendo Fun Club News, Tecmo used Dragon Ninja as a tentative title for the U.S. release. The title literally meant "Ninja Side-Story". According to an interview with developer Masato Kato, the staff, determining how to translate "Ryukenden" into English, went with Ninja Gaiden "because it sounded cool".

Ninja Gaiden is an action game developed and released by Tecmo, alongside the arcade game of the same name, which is a very different title. 

Ninja Gaiden was one of Tecmo's first NES games, alongside Tecmo Bowl, and was developed by a different team than the arcade version. According to developer Masato Kato, the term "ninja" was gaining popularity in North America, prompting Tecmo to develop a ninja-related game for the NES and Arcade. Both versions were directed by Hideo Yoshizawa (listed as "Sakurazaki" in the game's credits), who led the development teams of both this game and its arcade counterpart.

The game stars Ryu Hayabusa, who has travelled to America to avenge the death of his father by Jaquio.  Jaquio plans to rule the world using an ancient demon. In order to unleash the demon, he needs the power of the light and shadow statues. During his journey, Ryu meets an archaeologist named Walter Smith, and Irene and Foster of the CIA.

Ninja Gaiden is a side-scrolling platformer. Ryu has a health bar and a set number of lives for each Act, but can continue as many times as necessary. Ryu's main method of attack is his dragon sword, which can be used to hit enemies or destroy background objects, which drop items. Items include secondary weapons and spiritual power, which is needed to use secondary weapons, point pickups, freeze time, restore health, provide temporary invincibility, or grant an extra life.

Secondary weapons take up different amounts of spiritual power and include throwing stars, which are thrown straight ahead, windmill stars, which are thrown and return towards Ryu, the art of the fire wheel, which temporarily spins around Ryu, spinning jump slash, which attacks enemies while Ryu is jumping, and the flame attack, which fires a blast of fire upwards.

Ryu can cling onto walls and jump off in the opposite direction, which is a technique used to climb many areas in the game. If a ladder is present, he can freely climb up and down a wall. 

The gameplay was modeled after Konami's Castlevania, The development team wanted Ryu to be unique from other ninjas and designed him with a ninja vest, in order to place emphasis on his muscles, and a cowl that arched outward. They originally wanted to equip Ryu with high tech sensors and a helmet, but the idea was scrapped. 

The game features 6 Acts, which contain multiple levels, for a total of 20 levels. Cut scenes are shown between each stage to explain the story and provides a narrative level rarely seen in video games at the time. These included over 20 minutes of cinematic cut scenes in a system which Tecmo called the "Tecmo Theater".

Each act ends in a boss battle. The bosses include the malice four which are Barbarian, Bomberhead, Basaquer, and Bloody Malth.

The game was known for its high difficulty. Aside from the difficulty of the platforming and enemies, if a player died during one of the final 3 boss battles, the player is sent back to the beginning of the lengthy Act 6. This was originally a bug, but purposely left in. This is because it was Tecmo's policy to create harder games to challenge the Western audience.

The game was also known for being one of the most popular titles on the system, and still retains that status. It was also featured fairly prominently in the movie The Wizard.

A Ninja Gaiden novel was written by Seth Godin and released as part of Nintendo's Worlds of Power series.

The game was followed up by Ninja Gaiden 2: The Dark Sword of Chaos, and Ninja Gaiden 3: The Ancient Ship of Doom, both for the NES. The 3 games were re-released in the SNES collection Ninja Gaiden Trilogy, and are available as unlockables in the Xbox Ninja Gaiden game.