Shoot 'em ups such as SNK's "Ikari Warriors" (1986) featuring characters on foot, rather than spacecraft, became popular in the mid-1980s in the wake of action movies such as "." The origins of this type go back to "Sheriff" by Nintendo, released in 1979. Taito's "Front Line" (1982) established the upwards-scrolling formula later popularized by "Commando," in 1985. "Commando" also drew comparisons to Rambo and indeed 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. In 1986, Arsys Software released "WiBArm", a shooter that switched between a 2D side-scrolling view in outdoor areas to a fully 3D polygonal third-person perspective inside buildings, while bosses were fought in an arena-style 2D battle, with the game featuring a variety of weapons and equipment. In 1987, Square's "3-D WorldRunner" was an early stereoscopic 3-D shooter played from a third-person perspective, followed later that year by its sequel "JJ", and the following year by "Space Harrier 3-D" which used the SegaScope 3-D shutter glasses. That same year, Sega's "Thunder Blade" switched between both a top-down view and a third-person view, and introduced the use of force feedback, where the joystick vibrates. Also in 1987, Konami created "Contra" as an coin-op arcade game that was particularly acclaimed for its multi-directional aiming and two player cooperative gameplay. However, by the early 1990s and the popularity of 16-bit consoles, the scrolling shooter genre was overcrowded, with developers struggling to make their games stand out (one exception being the inventive "Gunstar Heroes," by Treasure).