SOS is a vertical-scrolling shooter arcade game

Arcade game

An arcade game is a coin-operated entertainment machine, usually installed in public businesses such as restaurants, bars, and amusement arcades. Most arcade games are video games, pinball machines, electro-mechanical games, redemption games, and merchandisers...

 that was released by Namco

Namco

is a Japanese corporation best known as a former video game developer and publisher. Following a merger with Bandai in September 2005, the two companies' game production assets were spun off into Namco Bandai Games on March 31, 2006. Namco Ltd. was re-established to continue domestic operation of...

in 1980.

Gameplay

The player controls a fighter plane called a "Shinryaku" which is situated at the bottom of the screen, while enemy planes fly down from above. The player may destroy them for 10 points each. Every few seconds, an "SOS" signal will sound and an arrow will point to either side of the screen, and the player must get there before it stops to receive 30 points and eliminate some of the enemy planes that have passed the Shinryaku. If 100 enemy planes make it past the Shinryaku, the game is instantly over.

Trivia

One of the reasons this game is infamous, is because of the "coffee breaks" it takes every 2000 points.