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 AmericanNinja 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 3Daction 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