When Nintendo released their Family Computer to the Japanese market in 1983, Namco was one of the first third-parties to offer games for the new system. Namco heavyweights like Pac-Man, Galaga and Dig Dug appeared over the next couple of years, all created by the same company that had released the arcade games. Two years later, Nintendo brought the Famicom to the U.S., redesigned and renamed as the Nintendo Entertainment System. Namco, still relying on other companies to import their arcade games at the time, did not immediately follow Nintendo to the States, and so other companies also worked to bring Namco's Nintendo offerings to American players. Not every Namco title was imported, though. Galaxian was among the missing, perhaps because no one thought the game would sell when sequel Galaga was also available.
Despite the apparent lack of faith, the Famicom's Galaxian is an excellent port, and is actually the first home version to get both the number and types of aliens in each wave exactly right. The Famicom's sound system can't quite duplicate Galaxian's original audio, but Namco brought it as close as they could, making this also the first home version with the same intro tune as the arcade game. The alien shapes and personalities are also nicely preserved, even if the difficulty seems to ramp up a little faster than in the original.
Maybe it's true that Galaxian would have had a hard time competing with Galaga for the attention of American gamers. If so, it certainly wouldn't have been for lack of trying. Fans of Galaxian will not be disappointed in this port, no matter which side of the ocean they're on.