Space Invaders

Space Invaders is an arcade game designed by Tomohiro Nishikado and released by Taito in Japan in July 1978, and in North America by Midway in November of the same year. The player moves a laser cannon along the bottom of the screen and shoots at a formation of aliens, five rows of eleven, that marches from side to side and steps down a row each time it reaches an edge. The aliens drop bombs; the cannon hides behind four bunkers that crumble as both sides hit them.^[1] The game ends when the aliens reach the ground.

The name of SARS Invaders, a game planned by Molecular Reality Corporation, is a pun on it.

Nishikado worked alone and built much of the hardware himself. He chose an Intel 8080 microprocessor driving a bitmapped display, after seeing what a microprocessor had done for Midway's Gun Fight. He was answering Atari's Breakout (1976), in which a paddle knocks out a wall of bricks, and he took the look of the aliens from The War of the Worlds and the setting in space from Space Battleship Yamato and Star Wars.^[1]

The aliens speed up as the player destroys them. Nishikado did not plan this. The processor took less time to draw each frame when there were fewer aliens to draw, so the formation moved faster as it thinned, and the last alien crosses the screen at a run. He kept the effect because it made the game more interesting. The four descending notes of the bass line, which loop under the whole game, speed up with it.^[1]

One flaw survived in the machines. At very close range the aliens' bombs could not hurt the cannon, and players learned to let the formation descend to the bottom row and shoot it from point-blank range, a technique called "Nagoya shooting". Taito decided against replacing the program a second time.^[1]

More than 100,000 machines had been installed in Japan by the end of 1978, and about 750,000 worldwide by the end of 1979, 400,000 of them in Japan. The version for the Atari 2600, released on March 10, 1980, was the first official license of an arcade game for a home console. It sold more than a million copies in its first year and almost 6.1 million by 1983, and it is usually counted as the first game that people bought a console in order to play.^[1] The arcade shooters that followed it include Galaga (1981), whose aliens dive at the player instead of marching, and Missile Command (1980).

The company's virology game was first called 2021: A SARS Odyssey, after the film 2001: A Space Odyssey. Its entry in the 2022 memo "Early Releases on Maxine's Quest" lists six influences, Galaga, Missile Command, Defender, Megamania, Star Raiders and Atari's Star Wars arcade game, and Space Invaders is not among them.^[2] It arrived with the new name. A company website of February 2026 listed the game as "SARS Invaders: (FKA 2021: A SARS Odyssey but we didn't ship in 2021 and had to change the name!)", and the founder has called the name "a pun on Space Invaders".^[3][4]

A second pun waits in the company's MoleculArcade, among five titles marked "Coming Soon". Molecular Invaders keeps the original's geometry and changes the cast: "Defend the cell membrane from waves of descending viral particles. Your antibodies fire upward".^[5] As of October 2026 neither game had been released.

• Asteroids (video game), Atari's 1979 shooter, which drew on it
• List of Molecular Reality Corporation puns
• List of works that inspired Molecular Reality Corporation