Galaga is a 1981 fixed shooter video game developed and published by Namco for Japanese and European arcades; it was distributed by Midway Manufacturing in North America. 

Development staff included Shigeru Yokoyama as chief planner, Toru Ogawa as hardware and programming lead, Hiroshi Ono as graphics lead, and Nobuyuki Ohnogi as sound and music lead. All would later work on such games as Pole Position, Super Pac-Man, Mappy, and Ridge Racer Evolution.  

A sequel to 1979's Galaxian, the player controls a starship and is tasked with destroying the Galaga forces in each stage while avoiding enemies and projectiles. Some enemies can capture a player's ship via a tractor beam, which can be rescued by another ship to give the player a "dual fighter" with additional firepower. This “dual fighter” mode was added to differentiate the game from other space themed games on the market, and was done as a later addition to the design process by Yokoyama after he recalled watching a sci-fi film with a tractor beam. 

The unique “Challenge Stage” feature of Galaga, where enemy fighters fly in from off screen and then fly directly at the player before leaving and not attacking in different patterns that grow more challenging over time, was the result of a serendipitous bug that occurred while Ogawa was programming. Yokoyama and Ogawa enjoyed the result of the bug so much that it became a core feature.

The name “Galaga” was a deliberate choice to incorporate the “Gal” of its predecessor Galaxian and the word “ga”, which in Japanese means moth.