Metroid (メトロイド, Metroid), is a 1986 platforming video game for the Nintendo Entertainment System. 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
In Super Smash Bros., the stage Planet Zebes is set on Zebes, a planet which first appears in the original Metroid. The stage's music is a remix of the Brinstar music. Various enemies (including Ridley, who uses his light purple appearance from Metroid) appear in the background. One of Samus' alternate costumes resembles the Varia Suit when missiles are selected in this game; this costume appears in every subsequent Smash Bros. game. Samus' victory theme is a remix of the "item collection jingle".
In Melee, two new stages originate from Metroid: Brinstar and Brinstar Depths. Brinstar is similar to Planet Zebes from original Smash Bros.. It has a new remix of the Brinstar theme, but portions of the music being a remix of the "Samus appearance jingle". Brinstar Depths is based on Kraid's area from Metroid, and has a remix of the theme from the same area; like Brinstar, part of the music is a remix of another track from Metroid, this time being the "item room" theme. Kraid appears in the background of Brinstar Depths, although he uses his Super Metroid appearance. Ridley appears in the opening movie and as a trophy, and both use his light purple color from Metroid, despite using his Super Metroid appearance as a base. A Metroid, a creature originating in this game, has a trophy.
In Brawl, Ridley is a boss. Norfair is a new stage, and Brinstar returns from Melee. Norfair has remixes of the Norfair theme and the ending theme, both from Metroid. Brinstar has both the Brinstar and Brinstar Depths themes from Melee. A Metroid appears as an Assist Trophy.
In Super Smash Bros. for Nintendo 3DS, Brinstar returns, retaining both themes from Brawl. Mother Brain and a Metroid appear as assist trophies. Zoomers appear in Smash Run, although they use their Super Metroid designation of "Geemer".
In Super Smash Bros. for Wii U, Metroid appears as a Masterpiece. Norfair returns from Brawl, and remixes of the title theme and escape theme are in the game. Mother Brain and a Metroid appear as assist trophies here, as well. Ridley appears as a boss in the game, but uses his Other M design. The Morph Ball, a power-up debuting in Metroid, has a trophy.