List of similarities between Metroid and Alien

The Metroid series appears to have borrowed elements and plots from the Alien film franchise. Yoshio Sakamoto has occasionally made comparisons and Nintendo Power #58 claims that Samus Aran's depiction in the Super Metroid comic is partly based on Ellen Ripley (As well as the Star Wars series' Leia Organa). Below is a list of perceived similarities between the series.

Metroid

 * Both Metroid and Alien feature a female lead protagonist, Ellen Ripley in Alien, Samus Aran in Metroid.
 * Director of Alien is named Ridley Scott. Miniboss in Metroid and antagonist in later games is named Ridley.
 * Nostromo's ship computer is called "Mother". Antagonist of Metroid is Mother Brain.
 * Alien features eponymous creatures called Aliens, whose first stage latches on to the face. Metroid features eponymous creatures called Metroids, whose first stage latches on to the head.
 * End of the film shows Ripley barely escaping from the exploding Nostromo. End of game shows Samus barely escaping from the exploding Tourian facilities. Both characters are the sole survivors of the explosion (apart from Ripley’s cat Jones).
 * Ripley ends up scantily clad near the end of the film. Samus ends up scantily clad near the end of the game if certain requirements are met.
 * The Ridley miniboss in Metroid slightly resembles the Alien creature.

Metroid II: Return of Samus

 * In Aliens, Ripley travels to the source of the Alien species, LV-426. In Metroid II, Samus travels to the source of the Metroid species, SR388.
 * Both films center around the female lead attempting to exterminate the eponymous species of their franchise.
 * Aliens go through a life cycle beginning with hatching out of an egg and then metamorphosing. Metroids also go through the process of metamorphosis.
 * Both the Metroids and Aliens molt and outgrow their shells as they mature.
 * The Zeta Metroids are known to spit a type of damaging fluid. The Xenomorphs in Alien 3 have been shown to spit acid as a form of attack.
 * The aforementioned Metroid also bears some resemblances to the Xenomorph species in terms of physical features.
 * Aliens features a final battle with the Queen Alien, the very Alien producing the entire species. Metroid II features the Queen Metroid, similarly.
 * Ripley saves and bonds with a surviving colonist, a young girl nicknamed Newt. Samus saves and bonds with a newly hatched Metroid, nicknamed "Baby".
 * Once again, Ripley ends up scantily clad at the end of the film, and Samus ends up scantily clad at the end of the game if requirements are met.

Super Metroid

 * In Alien3, Newt is killed. At the end of Super Metroid, the Baby sacrifices itself. Ripley also sacrifices herself at the end of the film.
 * In the Super Metroid comic, Samus’ appearance was a mix of Ripley’s as well as Princess Leia from Star Wars.
 * A body outside Kraid’s room may be a reference to the "Space Jockey" from the first Alien film.
 * Ki-Hunters have the ability to spit Acid at Samus. The Alien in Alien3 spat acid in one instance at the face of the prison janitor, knocking him into the ventilation fan and killing him.

Metroid Prime

 * The body of the Baby Sheegoth creature somewhat resembles the head of the Alien.

Metroid Fusion

 * In Alien Resurrection, Ripley is cloned and an Alien Queen embryo is surgically removed from her body. It leaves behind DNA that turns Ripley into an Alien/Human hybrid. Similarly, parts of Samus' Power Suit are surgically removed when she is at risk of death, and she is given a Metroid vaccine created from DNA cells of the Baby, turning her into a Metroid/Human hybrid.
 * The Genesis creatures pay homage to the locomotion of the Alien creatures in the films.
 * The appearance and lunging attack of the Fune/Nahime may be a reference to the inner jaw of the Alien.
 * Weyland-Yutani clones the Aliens from Ripley's embryo for use as bio-weapons. The Galactic Federation uses the Baby's cells to also create the Restricted Lab that Samus later discovers and destroys.
 * Interestingly enough, the Federation already seems to possess a bio-organic weapon for military purposes, the Nightmare.
 * The Alien creatures do not attack Ripley due to them thinking that she is one of them. The Metroids do not attack Samus for the same reason, with the exception of the Omega Metroid.
 * The scene where Samus discovers the Restricted Lab may have been inspired by the scene in Resurrection where Ripley discovers the lab containing her seven predecessor clones, all of which are heavily deformed. Both laboratories are ultimately destroyed by the female protagonist.
 * The Federation also wants to use the X Parasites and the SA-X for military purposes, similar to the intention of the Weyland-Yutani company throughout the Alien films.
 * The escape sequence for Fusion is strikingly similar to that of Aliens. In both sequences, Ripley/Samus are left stranded with no means of escape, and the Queen Alien/Omega Metroid attacking them. At the last minute, their ship flies in and rescues them, and they escape the station.
 * The Auriga spaceship that the entire film took place on is set by the android Call to collide with Earth. The Biologic Space Laboratories research station is set by Samus to collide with SR388.
 * Samus distrusted her ship's computer, but later came to accept and trust it after it was revealed to be Adam Malkovich. Similarly, Ripley distrusts Bishop 341-B, an android, due to experiences with an android in Alien, but he later redeems himself and earns Ripley’s trust.
 * A corrosive green liquid is seen in Sector 1. Aliens bleed corrosive green blood.
 * The X Parasites spread in a similar manner to the Xenomorphs in the Alien series. In this instance, Samus is infected and her infected suit parts are sent to the BSL, while in Alien Kane is brought onboard the Nostromo, along with the Chestburster inside him. Both events set the respective plots in motion. In Alien 2, Newt's father is infected and being brought back to the colony, therefore starting the whole infestation and deaths of everyone except for the protagonists.
 * In addition, both lifeforms parasite their hosts from within their bodies and eventually kill them upon reaching a mature stage.
 * In the beginning of the game, the survivors are all but rumored to be dead. However, Etecoons and Dachoras somehow managed to survive the X infestation for unknown reasons. This is eponymous with Newt, who was the only survivor of the colony during the infestation in Aliens.

Metroid Prime 2: Echoes

 * Aether having a turbulent atmosphere that damages the protagonist's ship and leaves them stranded on the planet is a concept that also appears in Alien, where the Nostromo lands on LV-426 until repairs are complete.
 * The Splinter hive in the Federation Marine' Ops base and the discovery of the dead troopers caught in webs is similar to the discovery of the Alien hive and cocooned colonists in the colony complex in Aliens.
 * The scene revealing that the Splinters managed to kill off the entire task force is similar to the hive discovery scene in Aliens, which kill all Marines except for Corporal Hicks and Privates Hudson and Vasquez, who all later die.
 * The scene where Dark Samus aims at the real Samus during their first encounter has been admitted to be based off a scene in Aliens.
 * Dark Samus resembles the Alien creature slightly due to her black coloring, skeletal feet and clawed fingers.
 * The Chykka boss resembles the second stage of the Alien life cycle, the Chestburster.
 * The character PFC G. Haley is the weakest Marine emotionally, similar to Private Hudson in Aliens. They are both later killed.

Metroid Prime 3: Corruption

 * The scene where Samus awakes from a nightmare (in which Dark Samus is reborn and is released from an exploding Phazon canister) might have been inspired by another nightmare scene in Aliens (in which a Chestburster erupts out of Ripley while she is in the hospital).
 * One scene during the invasion of Norion depicts Ghor fighting a Berserker Lord in his armorsuit. This is similar to the climax of Aliens, where Ripley battles the Alien Queen with an exosuit cargo loader.
 * The Berserker Lord's head strongly resembles that of a Queen Alien.

Metroid: Other M

 * Adam Malkovich is hostile towards Samus for leaving the Federation Army due to "a certain incident". Similarly, in Alien3 the superintendent Harold Andrews believes Ripley to be incredibly disruptive to the status quo in the prison when she crash-lands there. Anthony Higgs in Other M and Leonard Dillon in Alien3 are the only two inhostile toward Samus and Ripley.
 * The "Baby's Cry" coming from the Bottle Ship is based on the warning signal from the downed vessel on LV-426 in Alien.
 * The RB176 Ferrocrusher that Samus battles strongly resembles the loader that Ripley used at the end of Aliens. "Ferro" is also a character in Aliens.
 * MB's personality as a rogue android is likely inspired by that of Ash in Alien.
 * The scene where the Deleter kills K.G. Misawa by throwing him into Lava is similar to the scene of Ripley's death in Alien3.
 * Like Alien Resurrection, Samus was used without her knowledge to create bioweapons. MB was also created to form control between the Zebesians (Space Pirates, Metroids, etc) and herself. This mirrors Alien Resurrection quite closely as Ripley was cloned for a similar purpose; for the extraction of a Queen Alien which can reproduce Aliens. In Other M a Queen Metroid is also created, just like Alien Resurrection.