Metroid (メトロイド, Metroid) is a 1986 platforming video game for the Nintendo Entertainment System and the first installment in the Metroid series. The storyline is that the Space Pirates, led by Mother Brain, have come in control of energy-based lifeforms known as Metroids. Bounty hunter Samus Aran was hired by the Galactic Federation to take them down on the pirate's homeworld, Zebes.
In the Super Smash Bros. series
Samus Aran and Ridley both debuted from this game, the former being the playable protagonist while the latter is a major antagonist in almost every single game in the franchise, although in Metroid he serves as purely a boss. Ridley is a fighter in Super Smash Bros. Ultimate, but was a boss in Super Smash Bros. Brawl and Super Smash Bros. for Wii U.
The stage Planet Zebes is set on Zebes, a planet which first appears in the original Metroid. Brinstar resembles Planet Zebes, but has slightly different platforms. Brinstar Depths is based off of Kraid's area. Norfair is based off of a location from the game, although the design comes from Super Metroid and Metroid: Zero Mission.
The Screw Attack alters a character's first and second jumps (leaving any further jumps they may have unchanged), changing them to mimic Samus's up special move. In Metroid, the Screw Attack is a Chozo artifact that allows Samus to attack while somersaulting.
Mother Brain and a Metroid are both assist trophies that originate from this game. The former is the final boss of the game while the latter is a species that must be eradicated by Samus in future games.
"Title Theme - Metroid", "Brinstar (64)", "Brinstar (Melee)", "Brinstar (Brawl)", "Brinstar Depths (Melee)", "Norfair", "Escape", "Ending - Metroid", and "Brinstar Depths" all appear as tracks from Metroid in Ultimate.
In Smash 4