player to control the direction of flight and along with the earlier TwinBee (1985), is an early archetype of the "cute 'em up" subgenre. In 1986, Taito released KiKi KaiKai, an overhead multi-directional shooter. The game is notable for using a traditional fantasy setting in contrast to most shoot 'em up games filled with science fiction motifs. R-Type, an acclaimed side-scrolling shoot 'em up, was released in 1987 by Irem, employing slower paced scrolling than usual, with difficult, claustrophobic levels calling for methodical strategies. 1990's Raiden was the beginning of another acclaimed and enduring series to emerge from this period. Run and gun and rail shooters (1980s to early 1990s) Run and gun games became popular in the mid-1980s. These games feature characters on foot, rather than spacecraft, and often have military themes. The origins of this type of shooter go back to Sheriff by Nintendo, released in 1979. SNK's Sasuke vs. Commander (1980), which had relatively detailed background graphics for its time, pit a samurai against a horde of ninjas, along with boss fights. Taito's Front Line (1982) introduced the vertical scrolling format later popularized by Capcom's Commando (1985), which established the standard formula used by later run and gun games. Sega's Ninja Princess (1985), which released slightly before Commando, was a run and gun game that was distinctive for its feudal Japan setting and female ninja protagonist who throws shuriken and knives. SNK's TNK III, released later in 1985, combined the Front Line tank shooter format with unique rotary joystick controls, which they later combined with Commando-inspired run and gun gameplay to develop Ikari Warriors (1986), which further popularized run and gun shooters. Ikari Warriors also drew inspiration from the action film Rambo: First Blood Part II (1985), which it was originally intended to be an adaptation of. Contemporary critics considered military themes and protagonists similar to Rambo or Schwarzenegger prerequisites for a shoot 'em up, as opposed to an action-adventure game. The success of Commando and Ikari Warriors led to run and gun games becoming the dominant style of shoot 'em up during the late 1980s to early 1990s, with the term "shoot 'em up" itself becoming synonymous with "run and gun" during this period. Konami's Green Beret (1985), known as Rush'n Attack in North America, adapted the Commando formula to a side-scrolling format. Later notable side-scrolling run and gun shooters include Namco's Rolling Thunder (1986), which