film Game of Death, where Lee's character fights a different boss character on each floor as he ascends a pagoda. According to Matt Fox, it "one hundred percent defined" the beat 'em up genre, with variations of its plot structure used in virtually every scrolling beat 'em up since. There were numerous imitators, such as Black Belt (1986) and Kung Fu Kid (1987) on the Sega Master System. Other beat 'em ups that followed its single-plane side-scrolling format include arcade games such as Sega's My Hero and Flashgal (1985), Taito's The Ninja Warriors (1987), Data East's Bad Dudes Vs. DragonNinja (1988) and Namco's Splatterhouse (1988). Other titles such as Technōs Japan's Renegade (1986) and Double Dragon (1987), Capcom's Final Fight (1989) and Sega's Streets of Rage (1991) evolved the beat 'em up formula established by Kung-Fu Master with a belt-scrolling format. The boss battles had health meters for the player character and each boss, which led to the game temporarily becoming a one-on-one fighting game during boss battles. The Kung-Fu Master boss battles became the basis for the 1987 fighting game Street Fighter, which was directed by Kung-Fu Master designer Takashi Nishiyama after leaving Irem for Capcom. Following the release of Kung-Fu Master, Capcom was interested in hiring Nishiyama, who then led the development of Street Fighter. Nishiyama later left Capcom to run SNK's video game development division, creating the Neo Geo arcade system board and fighting games including Fatal Fury, Art of Fighting, Samurai Shodown and The King of Fighters. Side-scrolling character action games Kung-Fu Master was the most notable early example of a side-scrolling character action game, a genre of games that featured large sprite characters in colorful, side-scrolling environments, with the core gameplay consisting of fighting large groups of weaker enemies using attacks (or weapons) such as punches, kicks, guns, swords, ninjutsu or magic. This side-scrolling character action game format became popular during the mid-to-late 1980s, with arcade examples including ninja games such as Taito's The Legend of Kage (1985), Sega's Shinobi (1987), and Tecmo's Ninja Gaiden (1988) as well as run and gun video games such as Konami's Rush'n Attack and Namco's Rolling Thunder (1986). Kung-Fu Master was particularly the first and most influential side-scrolling martial arts action game, serving as the prototype for most martial arts games during the late 1980s, and also established the health meter mechanic as a standard feature in fighting games