"Ninja Gaiden II: The Dark Sword of Chaos, known in Japan as Ninja Ryukenden II: Ankoku no Jashinken and as Shadow Warriors 2 in Europe, is a side-scrolling platforming video game developed and published by Tecmo for the Nintendo Entertainment System (NES). It was released in Japan on April 6, 1990, in North America in May 1990, and in Europe on October 27, 1994. The game was later released for the Commodore Amiga and DOS-based PCs by GameTek in 1991. It was then released for the Wii's Virtual Console service on October 15, 2007 in North America. This game is the second installment in the Ninja Gaiden trilogy for the NES." Source: Wikipedia, "Ninja_Gaiden_II:_The_Dark_Sword_of_Chaos," available under the CC-BY-SA License.