SOS

Pilots take to the skies in SOS, a cooperative vertical shooter released in 1979 by K.K. Tokki under license from Namco. Players control a fighter plane, designated the 'Shinryaku,' and must defend against waves of descending enemy aircraft. Points are earned by destroying these hostile planes, but survival hinges on reacting quickly to timed "SOS" signals that appear onscreen; reaching the indicated location before the signal expires awards bonus points and clears some enemies from the playfield. The challenge escalates as more enemy planes appear, with instant game over if one hundred successfully pass beneath the player's aircraft. Two players can team up for a shared defensive effort, employing simple two-way joystick controls to maneuver their Shinryaku through the increasingly intense aerial barrage. Notably, SOS includes brief interludes every 2000 points where a cartoon character appears; these pauses became an unusual feature of the game’s design.