Space Invaders is a 1978 arcade game created by Tomohiro Nishikado. It was manufactured
and sold by Taito in Japan, and licensed in the United States by the Midway division of
Bally. Within the shooter genre, Space Invaders was the first fixed shooter and set the template
for the shoot 'em up genre. The goal is to defeat wave after wave of descending aliens
with a horizontally moving laser to earn as many points as possible.
Tomohiro Nishikado, spent a year designing the game and developing the necessary hardware
to produce it. The game's inspiration is reported to have come from varying sources, including
an adaptation of the mechanical game Space Monsters released by Taito in 1972, and a
dream about Japanese school children who are waiting for Santa Claus when they are attacked
by invading aliens. Nishikado himself has cited Atari's arcade game Breakout as his
inspiration. He aimed to create a shooting game that featured the same sense of achievement
from completing stages and destroying targets, but with more complex graphics. The game uses
a similar layout to that of Breakout but has altered game mechanics. Rather than bounce
a ball to attack static objects, players are given the ability to fire projectiles at moving
enemies. Early enemy designs for the game included
tanks, combat planes, and battleships. Nishikado, however, was not satisfied with the enemy
movements; technical limitations made it difficult to simulate flying. Humans would have been
easier to simulate, but the designer considered shooting them immoral. After the release of
the 1974 anime "Space Battleship Yamato" in Japan, and seeing a magazine feature about
Star Wars, he thought of using a space theme. Nishikado drew inspiration for the aliens
from H. G. Wells, The War of the Worlds, and created initial bitmap images after the octopus-like
aliens. Other alien designs were modeled after squids and crabs. The game was originally
titled Space Monsters after a popular song in Japan at the time, "Monster", but was changed
to Space Invaders by the Taito management. Because computers in Japan were not powerful
enough at the time to perform the complex tasks involved in designing and programming
Space Invaders, Nishikado had to design his own custom hardware and development tools
for the game. He created the arcade board using the latest microprocessors from the
United States, the Intel 8080, and sound from the Texas Instruments SN76477 sound chip.
The adoption of a microprocessor was inspired by Gun Fight, Midway's microprocessor adaptation
of Nishikado's earlier discrete logic game Western Gun. Despite the specially developed
hardware, Nishikado was unable to program the game as he wanted—the Control Program
board wasn’t powerful enough to display the graphics in color or move the enemies
faster—and he ended up considering the development of the game's hardware the most difficult
part of the whole process. While programming the game, Nishikado discovered that the processor
was able to render each frame of the alien's animation graphics faster when there were
fewer aliens on the screen. Since the alien's positions updated after each frame, this caused
the aliens to move across the screen at an increasing speed as more and more were destroyed.
Rather than design in compensation for the speed increase, he decided to keep it as a
challenging gameplay mechanism. Space Invaders was first released in a cocktail-table
format arcade cabinet with black-and-white graphics, while Midway released the Western
version in an upright cabinet; it used strips of orange and green cellophane over the screen
to simulate color graphics. The graphics are reflected onto a painted backdrop of a moon
against a starry background. Later Japanese releases used rainbow-colored cellophane,
such as T.T. Space Invaders in 1978, and were eventually followed by a version with a full-color
display. The cabinet artwork features large humanoid monsters not present in the game.
Nishikado attributes this to the artist basing the designs on the original title of "Space
Monsters", rather than referring to the actual in-game graphics.
In the first few months following its release in Japan, Space Invaders became very popular.
Specialty arcades opened with nothing but Space Invaders cabinets, and by the end of
1978 Taito had installed over 100,000 machines and grossed over US$600 million in Japan alone.
By 1980, Taito had sold over 300,000 Space Invaders machines in Japan, and 60,000 in
the United States. By 1982 Space Invaders had grossed $2 billion in quarters (equivalent
to almost $8 billion in 2020). This made it the best-selling video game and highest-grossing
"entertainment product" of its time, with comparisons made to the then highest-grossing
film Star Wars, which had grossed $486 million, with a net profit of $175 million. Space Invaders
earned Taito profits of over $500 million. The 1980 Atari 2600 version was the first
official licensing of an arcade game for consoles and became the first "killer app" for video
game consoles after quadrupling the system's sales. It sold over two million units in its
first year on sale as a home console game, making it the first title to sell over a million
cartridges. Other official ports were released for the Atari 8-bit computer line and Atari
5200 console, while Taito later released it for the Nintendo Famicom in 1985, but just
in Japan. Numerous unofficial clones were made.
Technology journalist Jason Whittaker credited the game with ending the video game crash
of 1977, caused by Pong clones flooding the market, and beginning the golden age of video
arcade games (1978–1980s). IGN attributed the launch of the "arcade phenomenon" in North
America in part to Space Invaders. Game Informer considered it, along with Pac-Man, one of
the most popular arcade games; it tapped into popular culture and generated excitement during
the golden age of arcades. As one of the earliest shooting games, Space
Invaders set precedents and helped pave the way for future titles and for the shooting
genre. Space Invaders popularized a more interactive style of gameplay, with the enemies responding
to the player-controlled cannon's movement, and was the first video game to popularize
the concept of achieving a high score, being the first to save the player's score. While
earlier shooting games allowed the player to shoot at targets, Space Invaders was the
first in which targets could fire back at the player. It was also the first game where
players were given multiple lives, and had to repel hordes of enemies, in addition to
being the first game to use a continuous background soundtrack, with four simple diatonic descending
bass notes repeating in a loop, which was dynamic and changed pace during stages, like
a heartbeat sound that increases pace as enemies approached.