SOS © 1979 Namco.
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.