Cookies help us deliver our Services. By using our Services, you agree to our use of cookies. Learn More.

Metroid Fusion Ending Explained

Long before Nintendo and series creator Yoshio Sakamoto resurrected "Metroid Dread" and turned it into the best-selling "Metroid" game to date, 2002's "Metroid Fusion" represented the last 'new' 2D platformer in the series. Given the excitement surrounding "Dread" and the game's still-relative newness on the market, many fans may feel inspired to revisit the older 2D entries (if they can find them) before playing the game voted best Action/Adventure at the 2021 Game Awards.

Gamers looking to complete "Metroid Fusion" and understand its connections to "Dread" may find the ending vague, even when compared to other entries in the series. In "Metroid 2: Return of Samus" and the remake "Samus Returns," the story ends with Samus defeating escaping SR388 with a Baby Metroid, which has imprinted upon her. In "Super Metroid," the story ends with the death of the Baby, which sacrifices itself to save Samus and help her take out the evil Mother Brain (again). "Metroid Fusion" breaks with this pattern, featuring a significant twist that may warrant further explanation for new fans of the series.

The biggest lingering question may be: Why does the sinister SA-X side with Samus for the final fight?

Samus and the X

Samus first encounters the X parasites on another mission to planet SR388. With the Metroids seemingly extinct at long last, the X have begun to overrun the planet and a neighboring research facility. Long story short, they infect Samus and corrupt the majority of her Power Suit. The player then witnesses the parasites reproduce this feat countless times, consuming and copying the bodies of monsters, constructs, and even other humans. In feeding off a host, the parasites assume both their fighting capabilities and their memories, making them especially deadly. As Samus says in the game, the X exist only to increase their own numbers.

The galaxy's most dangerous bounty hunter decides that the X must be eradicated in order to save the galaxy, even going so far as to ignore her commanding officer's orders in her pursuit. In turn, the X and SA-X recognize the threat of Samus to them, and assume the form of boss monsters like Nightmare, Yakuza (not the game), and Ridley himself to eliminate her. Meanwhile, the SA-X, a horrifying copy of Samus herself, stalks her throughout the game with the intent to kill.

Above all, the game makes clear that the X want to survive and spread their influence, and Samus becomes an increasingly formidable threat to their instinctive goals as she progresses through her adventure. So, why would the SA-X then decide to rescue its enemy? Because there is an even greater threat at work.

The X and the Metroids

Circling back to the prologue, the only way Samus survives her X infection is because the Federation develops a vaccine derived from the DNA of the X's natural predators: Metroids. Samus receives the medicine she needs to flush the X out of her system and recover immediately, albeit with her still-infected Power Suit out of commission. The vaccine also grants her the Metroid-like ability to absorb the X and even heal from them. Upon injection of the vaccine, Samus instantly became one of the greatest threats to the parasites, but not the greatest.

That distinction still belongs to the Metroids themselves. In "Metroid" series lore, the Chozo race created the Metroids for the exact purpose of giving the X a natural predator. The Metroid DNA makes Samus undoubtedly strong against the X, but not nearly as powerful as the real creatures.

The SA-X itself acknowledges Metroids as the greater threat... twice. Players find this out initially towards the later half of the game when Samus stumbles upon a lab in the B.S.L research station containing captive Metroids of all forms: Alpha, Gamma, Zeta, and most dangerous of all, Omega. Samus then learns the terrible truth: the Federation secretly captured some Metroids to experiment on for "peaceful applications." But Samus is not alone in her mistrust of this and outright hostility to the Federation's program.

The SA-X turns on its true enemy

Shortly after discovering the captive Metroids, players discover the SA-X completely ignoring Samus and firing missiles with reckless abandon as it tries to expunge every last Metroid. It recognizes the greater threat immediately, instinctively, and focuses in on it. It's this exact moment that propels the game towards its conclusion and the resolution of the SA-X's character arc. From that point on, the SA-X recognizes two existential threats to the proliferation of its species: Samus and the Metroids it inadvertently freed.

Following its duel with Samus, the SA-X flees before Samus can absorb its core. As the research station plummets towards the planet below, Samus has to race back to her ship to escape with her life. But when she arrives at the docking bay, the ship has vanished. In its place lies only the discarded shell of an Omega Metroid.

When all hope appears lost for Samus, the SA-X arrives to save her. With its own death and that of its species very near, it has a choice to make in its final moments: fall to the Omega Metroid or side with Samus to possibly defeat it. The SA-X appears to act solely on instinct to ensure the preservation of its kind, even if that means removing itself from the equation. However slim, merging with Samus to restore her power suit and Ice Beam presents the only chance for the SA-X to kill its natural predator.

For a 20-year-old game, the fact that fans still debate what happened in the ending of "Metroid Fusion" proves its longevity. "Metroid Dread" may be the latest and most profitable adventure in the series thus far, but "Fusion" has earned plenty of admiration for its gameplay, music, replayability, and ambiguous story — an excellent fusion of elements.