The list author says: "Metroid is a series of science fiction action-adventure video games conceived by designer Makoto Kano and artist Hiroji Kiyotake and primarily produced by Nintendo. Metroid chronicles the missions of bounty hunter Samus Aran who protects the galaxy from the depredations of the Space Pirates and their attempts to harness the power of fictional organisms such as the eponymous Metroids. It is noted for having one of the first female protagonists in a video game, and for its nonlinear gameplay. Metroid combines the platforming of Super Mario Bros. and the exploration aspect of The Legend of Zelda with a decidedly darker atmosphere.
As of 2011, the Metroid series consists of eleven games spanning most Nintendo consoles, from the Nintendo Entertainment System to the Wii. It is one of Nintendo's most successful franchises with 16 million games sold, and all of the Metroid games have received some level of critical acclaim. Samus Aran is featured in many other Nintendo-produced games along with secondary characters such as Mother Brain and Ridley. Nintendo has adapted several Metroid games into manga, and a live-action movie has been considered.
The name "Metroid" is a portmanteau of the words "metro" (as in rapid transit) and android, and was meant to allude to the mainly underground setting of the first game as well as its robot-like protagonist."