The series was originally known as Ninja Ryukenden (忍者龍剣伝, Ninja Ryūkenden?, lit. "Legend of the Ninja Dragon Sword") in Japan. The word "Gaiden" in the North American Ninja Gaiden title means "side-story" in Japanese, even though the Ninja Gaiden series is not a spinoff of a previous series. The original arcade version and first two NES games were released as Shadow Warriors in the PAL region.
The series gained popularity on the 8-bit Nintendo Entertainment System for its tight action-platform gameplay, catchy music and, according to G4's X-Play, was also the first console game to have the story presented in cinematic cutscenes. The 8-bit trilogy was enhanced for the 16-bit Super NES in 1995. A new game, titled Ninja Gaiden, was released in 2004 as a 3D action game on the Xbox, developed by Team Ninja, the makers of Dead or Alive. The Ninja Gaiden franchise is well-known for its high degree of difficulty, particularly the original NES version and the Xbox revival