Metroid (Japanese: メトロイド, Hepburn: Metoroido?) is a series of science fiction action-adventure video games by Nintendo. It 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 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, with releases on every Nintendo home and portable console except the Nintendo 64 (not counting Super Smash Bros), Game Boy Color, and the Virtual Boy (Not counting Samus's appearance in Galactic Pinball). As well as being one of Nintendo's most financially successful franchises with over 16 million games sold, it is also one of the company's most highly acclaimed series, with a GameRankings average score of 85% across all eleven titles.