| released =
| genre = Fixed shooter
| modes = Single-player, multiplayer
is a 1978 shoot 'em up game developed and published by Taito for arcades. Taito released it in Japan in July 1978 and overseas through a partnership with Midway Manufacturing later that year. Space Invaders was the first video game with endless gameplay and the first fixed shooter, setting the template for the genre. The goal is to defeat waves of descending aliens with a horizontally moving laser cannon to earn as many points as possible.
Designer Tomohiro Nishikado drew inspiration from video games such as Gun Fight and Breakout, electro-mechanical target shooting games, and science fiction narratives such as the novel The War of the Worlds, the anime Space Battleship Yamato, and the film Star Wars. To complete development, he had to design custom hardware and development tools to use the features in microprocessor technology, which was new to him. Upon release, Space Invaders quickly became a commercial success worldwide; by 1982, it had grossed ($ billion in -adjusted terms), with a net profit of ($ billion in terms). This made it the best-selling video game and highest-grossing entertainment product at the time, and the highest-grossing video game yet. It is also one of the highest-grossing media franchises of all time.
Space Invaders is considered one of the most influential and greatest video games ever, having ushered in the golden age of arcade video games and Japan's long-lasting global success in the video games industry. It inspired several prolific game designers to join the industry and influenced numerous games across different genres. The game has been ported and re-released in various forms, including the 1980 Atari 2600 version, which quadrupled sales of the Atari 2600 console and became the first killer app for video game consoles. The pixelated enemy alien has become a pop culture icon, often representing video games as a whole. The game has spawned dozens of sequels and remakes, been the inspiration for numerous pieces of art and music, been parodied across media, and been the focus of several pieces of legislation to limit access to video games.
Gameplay
thumb|left|alt=A vertical rectangular video game screenshot that is a digital representation of a battle between aliens and a laser cannon. The white aliens hover above four green, inverted U-shaped blocks. Below the blocks is a smaller horizontal block with a triangle on its top.|The player-controlled laser cannon (bottom center) shoots the aliens (center) as they descend. Game statistics, like the current score and remaining lives, are tracked above and below the playing field.
Space Invaders is a fixed shooter in which the player moves a laser cannon, referred to as a "Laser Base", horizontally across the bottom of the screen and fires at a group of the titular alien invaders overhead. The invaders begin as five rows of eleven—the amount differs in some versions—that move left and right as a group, advancing on the shooter by shifting downward each time they reach a screen edge. The goal is to eliminate all the invaders by shooting them. Regardless of how many game lives remaining the player has, the game ends if the aliens reach the bottom of the screen.
The aliens attempt to destroy the player's cannon by firing projectiles. The laser cannon is partially protected by stationary defense bunkers that are gradually destroyed from above by the invaders; the bottom will be destroyed if the player fires when beneath one. As the invaders are defeated, their movement, as well as the accompanying music, speeds up. Defeating all the aliens brings another wave that starts lower, a loop that can continue endlessly. A special "mystery ship" will occasionally move across the top of the screen and award bonus points if destroyed. Because he worked alone and handmade many of the development tools, the process incurred minimal costs. Taito originally did not credit a designer as anonymity was a required part of Nishikado's contract with the company. Nishikado noted that Breakout-style games were very popular in Japan in 1977. He was a fan of the game and aimed to create something better.
To improve the design, Nishikado felt the targets should have an interesting shape. The designer believed animating human characters would have been easier to program, but he considered shooting them immoral. Nishikado also said that shooting people was frowned upon. and seeing a magazine feature about the 1977 Star Wars, he thought of using a space theme. The game outputs monaural sound hosted by a combination of analog circuitry and a Texas Instruments SN76477 sound chip.
The adoption of a microprocessor was inspired by the 1975 arcade game Gun Fight, Midway's microprocessor adaptation of Nishikado's earlier discrete logic game Western Gun, after the designer was impressed by the improved graphics and smoother animation of Midway's version. At the time, Taito had licensed Midway's technology to use in its games. Nishikado used Midway's arcade board as a motherboard and created additional boards and circuitry to expand the capabilities.
As microprocessors were manufactured in the United States, Nishikado had to rely on his English skills, which he described as limited, to translate the reference material. He attributes his previous experience working with integrated circuits and learning assembly language during his university studies with helping him learn how to interact with the new hardware. Kamei spent four to five months on the audio circuitry for Space Invaders while also working on another game, Blue Shark. As management had prioritized Blue Shark, his work on Space Invaders was hurried in order to have both games ready for an unveiling event in the summer of 1978. Kamei decided to reuse parts and designs from other Taito games to meet the deadline. He replaced resistors and capacitors to adjust the pitch and duration of sound effects he created for Blue Shark. To create the invaders' moving sound effect, Kamei reused the 556 timer integrated circuit from Super Speed Race. the accompanying audio sped up as well. The company unveiled the game to businesses in June 1978. The focus of the event was Blue Shark, which Taito management believed would be more successful, and Space Invaders was included later during the event planning. Taito first released an upright arcade cabinet, which it announced in August 1978. The next month, the company released a cocktail-table cabinet version, which was named T.T. Space Invaders in Japan to indicate it was a "table-top" version. Taito then submitted a trademark request for the game's name with the Japan Patent Office on September 18, 1978.
Soon after release, the developers became aware of a bug with the coin mechanism. Since only a few hundred units had been released at the time, Taito was able to apply a fix by replacing the machines' read-only memory (ROM). To cope with the demand, Taito licensed the overseas rights to Midway for distribution outside of Japan near the end of 1978. Midway released upright and cocktail versions. By December 1978, Taito had to import Midway cabinets into Japan to meet the country's demand. It added Japanese instruction cards to the cabinets and referred to them as Space Invaders M. The company also released a color version of T.T. Space Invaders that same month. Taito then filed a trademark request for its arcade game with the United States Patent and Trademark Office on December 10, 1979. The company produced 200,000–300,000 units for the Japanese market by June 1979 and increased production to 25,000–30,000 units per month with Taito projecting to manufacture 400,000 machines in Japan before the year end. the number of units in the United States eventually reached 72,000 by 1982. Nishikado wanted to design newer hardware to stay competitive, but the widespread demand led Taito to support the existing Space Invaders hardware by creating new games compatible with it. This provided other companies time to develop technology that could match Taito's.
The 1980 port to the Atari 2600 was the first official licensing of an arcade game for consoles and became the first killer app for home video game consoles after quadrupling the system's sales. Other official home releases include a 1980 conversion for Atari 8-bit computers and a 1982 release for the Atari 5200 console. Taito released its own version for the Nintendo Famicom in 1985 exclusively in Japan. By 1982, versions of Space Invaders were available for handheld electronic game devices, tabletop dedicated consoles, home computers, watches and pocket calculators. At the time, software and video games were not formally recognized as copyrighted works under Japanese copyright law. Clone examples include the 1979 Super Invader for Apple computers, Epoch Co.'s 1980 TV Vader dedicated home console, and the 1981 TI Invaders for the TI-99/4A computer; the latter became the top-selling game for its platform by the end of 1982. The influx of clones led to the term "Invader game" to identify the generic classification of games. Unofficial copies dominated the video game market in South Korea, and the market demand for the machine's hardware spurred the early growth of Korea's semiconductor industry.
Reception
Space Invaders initially received mixed responses from within Taito and little interest from Japanese amusement arcade owners. Nishikado's colleagues praised it, applauding his achievement while queuing up to play, whereas his bosses predicted low sales as games often ended more quickly than timer-based arcade games. While amusement arcade owners initially rejected it, pachinko parlors and bowling alleys adopted the game; Space Invaders caught on in those businesses, with many parlors and alleys installing additional cabinets.
A year after its release, Space Invaders became the arcade game industry's all-time best-seller. It remained the top arcade game for three years through 1980. It had grossed more than by 1979 (equivalent to in ). In 1981, the game earned weekly in arcades in the United States, second only to Pac-Man. The Arcade Awards ceremony was created that same year to honor the best video games, with Space Invaders winning the first Best Coin-Op Electronic Game award. By 1982, it had grossed $2 billion (equivalent to $ in ), with a net profit of $450 million (equivalent to $ in ).
thumb|alt=Closeup of a black flat electronic device with a black plastic video game cartridge inserted into the receptacle slot on top. The slot is flanked on both sides by sets of two switches. The cartridge's label reads "Space Invaders".|Atari 2600 home console with a Space Invaders cartridge, one of the system's best selling games, at the [[Etopia Centre for Arts & Technology.]]
Ports have received mixed reviews; the Atari 2600 version was successful, while the Famicom version was poorly received. Bill Kunkel and Frank Laney in Video magazine found the variants on the arcade game interesting but suggested that purists will probably focus on the original version of the game included. Media writer Howard J. Blumenthal suggested that it requires skilled agility and hand-eye coordination and concluded that it was "a highly competitive reaction game, and one of the best available." Electronic Games magazine writers rated the game a perfect ten overall, noting high rankings for single-player gameplay, while only finding the game's graphics and sound to be merely good. The writers also reviewed the port for Atari's 8-bit home computers, complimenting the game for its excelling gameplay while finding its graphics and sound and enjoyment as a one-player game to be merely "good". Conversely, an editor for the Personal Computers & Games book found this version to be unfaithful to the original game, recommending Roklan's Deluxe Invaders for an experience more attuned to Taito's arcade game.