|Position in Timeline|
|First Game||Release Date||Metroid II: Return of Samus|
|First Game||Metroid Chronology||Metroid Prime / Metroid Prime Pinball / Metroid Prime Trilogy|
|This article is about Metroid, the first Metroid game. For other uses, see Metroid (disambiguation).|
 Manual Preface
In the year 2000 of the history of the cosmos, representatives from the many different planets in the galaxy established a congress called the Galactic Federation, and an age of prosperity began. A successful exchange of cultures and civilization resulted, and thousands of interstellar spaceships ferried back and forth between planets, but Space Pirates also appeared to attack the spaceships.
The Federation Bureau created the Galactic Federation Police, but the attacks of the Space Pirates were strong, and it was difficult to catch them in the vastness of space. To counter the attacks of the Space Pirates, the Galactic Federation called together courageous warriors, granting them large bounties for capture of Space Pirates. These space bounty hunters became known as "space hunters".
In the year 20X5 of the history of the cosmos, Space Pirates attacked a deep-space research spaceship, seizing a capsule containing an unknown life-form recently discovered on Planet SR-388. Though in a state of suspended animation, the life form could be reactivated, and multiplied, when exposed to beta rays for 24 hours. This unknown life-form, suspected as the cause of SR-388's destroyed civilization, was named Metroid by the Federation researchers.
Fearing that the Space Pirates intend to multiply Metroids and use it as a weapon, the Galactic Federation Police launched an assault on Planet Zebes, the Space Pirate headquarters where the Metroids are being held. Zebes is a natural fortress, and resistance of the Space Pirates was too strong. As the attacks on the planet fail, preparations made to multiply the Metroids.
As a last resort, the Federation Police hire a space hunter to infiltrate Zebes, stop the plans to multiply the Metroids, and destroy Mother Brain, the leader of the Space Pirate operation on Zebes.
The Federation Police hire Samus Aran, considered the greatest of all space hunters. The victor of many prior missions, Samus is surgically strengthened by robotics, to the point of having superpowers. Samus's Power Suit causes even the Space Pirates to fear, as it is capable of absorbing an enemy's power.
The interior of Zebes is a dangerous maze, with enemy Space Pirates lurking around every corner. With time running out, can Samus destroy the Metroids and save the Galaxy?
 Planet Zebes
As Samus fights her way through the labyrinths of planet Zebes on her quest to stop the Space Pirates from using Metroids as a weapon, she finds upgrades to her Power Suit on statues left behind by the Chozo. Using these upgrades, Samus fights her way through Brinstar, a region of Zebes, to find Kraid's hideout.
In Tourian, the corpses of Space Pirates litter the ground, and Samus soon discovers that Metroids are the cause. The Space Pirates succeeded in multiplying the original Metroids, and Tourian has become overrun by the new Metroids. Samus fights her way through Tourian defeating the Metroids by freezing them with her Ice Beam and shooting them with Missiles, both of which were acquired from Chozo Statues.
Deep in Tourian, Samus encounters Mother Brain, protected by five barriers of Zebetite. Using Missiles, Samus destroys the barriers and defeats Mother Brain. Mother Brain's defeat triggers a self-destruct sequence, and Samus is forced to escape Zebes in under three minutes.
- Move Pad – Moves left, right and points gun upwards.
- A – Jump
- B – Shoot Power Beam/Missiles
- START – Pause
- SELECT – Switch to Missiles
Based on the amount of time in which the player beats the game, there are five different possible endings. The possible endings are:
- 10 or more hours: Samus covers her face and turns her back to the player.
- Under 10 hours: Samus faces the player with one arm raised in the air.
- Under 5 hours: Samus removes her helmet, revealing that she is a woman.
- Under 3 hours: Samus removes her Power Suit, and is seen in a purple leotard.
- Under 1 hour: Samus removes her Power Suit, and is seen in a bikini.
 Later Releases
Metroid was later remade in the game Metroid: Zero Mission, which also included the original game. The game has also been released on the Wii Shop Channel, downloadable for 500 Wii points as a Virtual Console game. The game has also been released at no price to 3DS owners who are a part of the 3DS Ambassador Program as part of the 3DS Virtual Console. It will later be released to the public for an unknown cost. The Virtual Console versions do not have additional features beyond control updates. However, it is worthy to note that the electronic manual for the 3DS version describes the "secret" method of saving involving using the second player's controller. The game was released on July 12, 2013 in the Wii U eShop for $4.99, as a Virtual Console game.
- If the player completes a playthrough as suitless Samus in under an hour, Samus's bikini in the ending will be skimpier than usual.