Short answers, pulled from the story.
Space Invaders was designed by Tomohiro Nishikado and developed and published by Taito. It was released in Japan in July 1978 and distributed overseas through a partnership with Midway Manufacturing later that year.
By 1982, Space Invaders had grossed $3.8 billion worldwide with a net profit of $450 million, making it the highest-grossing entertainment product of its time. For comparison, the then highest-grossing film, Star Wars, had earned $486 million with a net profit of $175 million in the early 1980s.
Nishikado originally designed enemies as tanks, combat planes, and battleships, but found them technically difficult to animate. After seeing the 1974 anime Space Battleship Yamato and a magazine feature on the 1977 film Star Wars, he settled on a space theme. He drew the alien designs from H.G. Wells' novel The War of the Worlds, creating initial bitmaps based on octopus-like creatures, with additional designs modeled on squids and crabs.
The speed increase was an unintended consequence of the Intel 8080 CPU's processing limits. The processor rendered alien animation frames faster when fewer aliens were on screen, and because alien positions updated after each frame, fewer enemies moved faster. Nishikado discovered this while programming and chose to keep it as a gameplay feature rather than correct it.
The 1980 port of Space Invaders to the Atari 2600 was the first official licensing of an arcade game for a home console, and it quadrupled the console's sales. It sold over one million units in its first year, more than 4.2 million copies by the end of 1981, and nearly 6.1 million cartridges by 1983, making it the best-selling Atari 2600 game until Pac-Man arrived in 1982.
Shigeru Miyamoto, creator of Donkey Kong and Mario, said Space Invaders led him to pursue game design as a career. Pokémon creator Satoshi Tajiri wanted to make a Space Invaders sequel after playing it in junior high school. Hideo Kojima of Metal Gear, Eugene Jarvis who created Defender, and Doom creators John Romero and John Carmack all named Space Invaders as their formative introduction to video games.