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Even though Space Invaders used some of the latest hardware for the time, its creator, Tomohiro Nishikado, discovered that the processer wasn't powerful enough to run the game as intended (with the aliens moving at a constant speed), and instead rendered the alien graphics faster when fewer were on screen. Rather than design the game to compensate for the speed increase, he decided to keep it as a challenging gameplay mechanic.
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When Space Invaders was released in Japan, it was so popular that it caused a temporary shortage of the 100-yen coin, the coin most commonly used for arcade machines.
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The invaders in the game were originally intended to be airplanes, but the vehicle movements appeared jittery. Tomohiro Nishikado, the game's creator, then wanted to use human targets instead, however Taito's president was against the idea. It was eventually settled on having aliens after the recent popularity of Star Wars, with their designs inspired by the buglike aliens from the novel "The War of the Worlds" by H. G. Wells.
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Tomohiro Nishikado, the game's creator, wanted to create a game that was better than the Atari game "Breakout", which he was hooked on at the time. Based on the sense of accomplishment and exhilaration from breaking the targets, Nishikado wanted to improve upon this by giving the targets a more interesting shape and by turning it into a shooting game.
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Tomohiro Nishikado, the game's creator, wasn't too good at playing video games and was only able to balance the game based on other people's feedback. He admitted that he had trouble making it past the first level and that he would've made the game a lot easier had he balanced it only on his own experiences.
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Taito's upper-level sales management originally had no faith in the game prior to its release. When Tomohiro Nishikado, the game's creator, showed to them a work-in-progress version of the game, they weren't very impressed with it as they couldn't keep up with its pace. Even some arcade operators who were shown the game weren't positive towards it either, resulting in very few orders being placed.
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After the game's release, the game's creator, Tomohiro Nishikado, was contractually obliged by Taito not to reveal that he was the game's designer. He would however visit Tokyo arcades to watch people play the game and would worry that there might be critical bugs in the game, and that the people playing might encounter them.

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