The early 1980s is considered the Golden Age of video games, thanks in part to the many unique and innovative arcade games that were published during that time. But in the 1970s, when the industry was just getting established, "innovative" often wasn't the word of the day. If one company had a good idea, gamers could count on other companies releasing games with the very same idea. Even Atari's Pong wasn't the first time someone made table tennis into a video game. So when Space Invaders became a massive hit for Taito in 1978, it was inevitable some other company would seek to duplicate its success. Namco did just that, and struck gold the following year when they released Galaxian.
To Namco's credit, they didn't just copy Space Invaders, but instead sought to improve upon it. Where the aliens always stay in the same formation and always follow the same pattern of attack in Space Invaders, Galaxian features aliens of different personalities, with every alien capable of attacking independently of its comrades. Also unlike Space Invaders, Galaxian offers no protective shields or other extra defences against the aliens. These elements certainly helped Galaxian steal attention from the still-profitable Space Invaders, but Namco didn't stop there. Where previous arcade games, including Space Invaders, were either in black and white or had "false" color thanks to transparent overlays, Galaxian was the first arcade game presented in true color. Dazzling aliens and a glittering starfield set a new standard for arcade game graphics, and Galaxian escaped the shadow of Space Invaders to become a true hit.
Namco continued to tinker with the Space Invaders blueprint, and in 1981 they released a sequel to Galaxian, named Galaga. Galaga all but eclipsed its predescesor, and eventually became one of the most famous arcade games of all time. The original still has a healthy share of fans, however, and remains a staple among competitive players. Namco has also helped keep the memory of Galaxian alive by occasionally sneaking the iconic flagship into a new release.