Metroid is a series of science fiction games published by Nintendo. They feature the missions of the space-faring bounty hunter Samus Aran.
The original Metroid was released in 1986, and was one of the first games of its type for any system, let alone the NES. This action-platformer featured an open world that could be explored by using collectable upgrades, and featured a number of different endings. The game, though eventually overshadowed by its successors, is considered responsible for creating an entire genre of open-ended platformers.
Metroid II: The Return of Samus was an early Game Boy title, released in 1991. The game was significantly more straightforward than the original, yet managed to keep the former game's style intact.
1994's Super Metroid is considered by many to be the pinnacle of the series, refining the formula of the first two games and adding new elements such as a true map and some more iconic upgrade as the Power Bombs.
The Metroid series then went on hiatus for the greater part of a decade, with the exception of Metroid 2 DX for the Game Boy Color, which was a port of the Game Boy original. Samus would also appear in 1999's crossover fighter Super Smash Bros.
The Metroid series finally reemerged in 2002 on two fronts. First, there was the Nintendo-developed Metroid Fusion for the Game Boy Advance. IT was also known as Metroid 4, and was the direct followup to Super Metroid.
The other front was Retro's first person adventure game Metroid Prime. It re-imagined the series from a 3D first-person perspective. The game was possibly the best received in series history, and had two direct sequels, in 2004 and 2007.
2004 also brought Metroid: Zero mission, a remake of the original game that incorporated elements of Super Metroid and Metroid Fusion.
The most recent entry in the series is 2010's Metroid: Other M, designed by the creator of the series Yoshio Sakamoto. A 3D action game, it was one of the less popular entries in the series both critically and commercially, and has seemingly put the series on hiatus once again.
The ten games in the Metroid series have all been well received to some extent, with some, such as Super and Prime, being considered among the greatest games ever created. Furthermore, the Metroid series is considered to be responsible for the creation of an entire genre of games. Even other Nintendo franchises, such as Ice Climber, would come to adopt the formula.
Sales-wise, the Metroid series has done fairly well, though not as well as many other Nintendo franchises. The ten games in the series have sold a combined total of almost 20 million copies worldwide, including remakes and retail re-releases.