This game, considered to be the shoot'em up precursor was released in 1978 on arcade cabinets.
The principle of the game is simple: the player controls a laser cannon by moving it horizontally across the bottom of the screen and fires at descending aliens.
The game got so successful and popular that 100-yen coins used in arcade cabinets became rarer.
Japan government had to increase the coin production (some sources say they had to triple, others to quadruple) to provide for the players.

This game has been having a considerable influence for more than 30 years over the video game field and has been imitated numerous times. It was first the work of a single man, Tomohiro Nishikado.
There are several fun facts about this classic game such as the fact that it was not wanted that the game's speed increases. The speed increase is a result of hardwares back then which were hardly sufficient for the game to run properly. Display was very slow at the beginning and the fewer ennemies were on the screen, the easier it was for the processor to render the graphics and the faster the aliens scrolled. Rather than programming the game to compensate for the speed increase, it was decided to keep it as a challenging gameplay mechanic.