Metroid is an action-adventure game developed and published by Nintendo. The first installment in the Metroid series, it was originally released in Japan for the Family Computer Disk System peripheral in August 1986. North America received a release in August 1987 on the Nintendo Entertainment System in the Game Pak ROM cartridge format, with the European release following in January 1988. Set on the planet Zebes, the story follows Samus Aran as she attempts to retrieve the parasitic Metroid organisms that were stolen by Space Pirates, who plan to replicate the Metroids by exposing them to beta rays and then use them as biological weapons to destroy Samus and all who oppose them. The game was developed by Nintendo Research & Development 1 (Nintendo R&D1) and Intelligent Systems. It was produced by Gunpei Yokoi, directed by Satoru Okada and Masao Yamamoto, and scored by Hirokazu Tanaka. It pioneered the Metroidvania genre, focusing on exploration and searching for power-ups used to reach previously inaccessible areas. Its varied endings for fast completion times made it an early popular title for speedrunning. It was also lauded for being one of the first video games to showcase a female protagonist. Metroid was both a critical and commercial success. Reviewers praised its graphics, soundtrack, and tight controls. Nintendo Power ranked it 11th on their list of the best games for a Nintendo console. On Top 100 Games lists, it was ranked 7th by Game Informer and 69th by Electronic Gaming Monthly. In 2004, the Game Boy Advance received a re-release as part of the Classic NES Series and a remake, Metroid: Zero Mission, with updated visuals and gameplay. It was emulated for the Virtual Console service on various Nintendo platforms since 2007 and on Nintendo Switch Online.