In the year 20X5, a deep-space research vessel discovered a dangerous parasite on the planet SR388 named "Metroid". The research vessel was attacked by Space Pirates who stole the Metroid for use as a bio-weapon. All assaults on the Space Pirate fortress planet of Zebes failed. As a last resort, a lone Space Hunter named Samus Aran is sent deep into the planet to neutralise the threat.
Samus must explore the cavern mazes of Zebes, powering up the Power Suit to reach new areas and take down the leaders of the Space Pirates. Only then can Samus face the Mother Brain and her army of Metroids in a battle that will decide the fate of the galaxy.
Fierce creatures that crawl along surfaces with its sticky feet. The yellow types are weaker than the red type. Zoomer is the first enemy Samus will meet on Zebes.
Common enemies in Brinstar and Kraid's Hideout. They stick to the ceiling and drop down when Samus walks underneath. After burying itself in the ground, it explodes into deadly shards.
Strong flying enemies that swoop down to attack Samus. They retreat back to the ceiling when Samus jumps.
Brainless flying creatures that travel back and forth in a set area. You can't destroy them with the beam or missiles, but they can be frozen with the Ice Beam and used as stepping stones.
Flying enemies that travel in a wave pattern. They can be difficult to hit and can take quite a lot of hits with the Beam weapon.
Flying creatures that rise out of air holes, lining up and charging at Samus. The yellow ones can be defeated with one shot of the Beam, while the red ones take two shots.
Small, weak creatures that attack in swarms. They can travel through solid surfaces to attack, and are defeated with a single beam.
A creature whose body is covered in fireproof wool, protecting it from the heat of Norfair. It takes two hits with the Beam to defeat the blue Nova and four to defeat the red Nova.
The most powerful creatures in the Norfair area. The energy in their bodies allows their skin to generate fire, allowing them to swoop around with jets on their feet.
Poisonous bubbles of lava emerging from air holes that fire rocks out. They have no life force, so avoid the eruptions to pass by safely.
Advanced versions of the Ripper that generate internal fire, making them much faster than their Brinstar cousins. As with the Ripper, it cannot be defeated with the Beam or Missiles.
Small, weak creatures from Norfair that travel in swarms and can move through solid objects. They can be defeated with one hit.
Flying creatures that emerge from air holes and charge at Samus. They are covered in a hard shell, and the red Gamet is twice as strong as the blue Gamet.
The result of Mother Brain breathing life force into the molten rock. Multiviola is very strong and bounces off the walls. The Multiviolas in Norfair move more slowly than the ones found in Ridley's Hideout.
Creatures that live in the lava of Norfair. They leap out at regular intervals to catch prey. You can either hit them several times with the Beam or time their jumps to avoid them.
An ancient creature that lives in the Norfair lava. It sticks its head out of the lava and blows fire at Samus.
Boneless creatures that crawl along the surfaces of Kraid's Hideout. The green ones are weaker than the blue ones.
Fierce flying creatures that emerge from the air holes in Kraid's Hideout and charge at Samus. The brown Geega is stronger than the yellow Geega.
Weak, flying creatures that travel in swarms and can travel through solid objects. They are the weakest enemies in Kraid's Hideout.
Powerful creatures that leap around on the floor and ceilings of Kraid's Hideout. They can withstand a lot of hits with the beam, but are more easily defeated with missiles.
The larvae of the Multiviola. It crawls along the ground in Ridley's Hideout. It takes two hits with the Beam to defeat the blue Viola and four to defeat the yellow Viola.
The weakest creatures in Ridley's Hideout. They fly out of air holes and charge at Samus. The blue ones can be defeated with one shot from the beam, while the yellow variety takes two hits.
A swooping, horned creature that appears in Ridley's Hideout. It drops down to attack Samus and then retreats back to the ceiling. It can be defeated with a single missile or several shots of the Beam weapon.
Extremely strong creatures that hop around on the ground and ceiling. They can deal a lot of damage to Samus and can withstand a lot of hits with the Beam weapon. They can be defeated more easily with Missiles or the Screw Attack.
A life-support system that blocks your path to the Mother Brain but doesn't attack or damage Samus. Keep hitting it with missiles until it breaks or it will slowly regenerate.
Deadly rings of energy that float around in the final chamber where the Mother Brain resides. They aren't very strong, but many of them appear all at once.
An unusual, energy-drinking parasite discovered on the planet SR388. Mother Brain has successfully bred a whole host of Metroids that appear in Tourian. If it managed to attach itself to Samus it drains the energy meter rapidly. Use Bombs to detach the Metroid. It can only be defeated by freezing it with the Ice Beam and then hitting it with 5 missiles.
A horned creature that can be found in first Hideout. It attacks with barbs that it fires from its stomach and spinning horns from its back. Avoid the onslaught and hit it with missiles or bombs. Defeating Kraid increases Samus's missile capacity by 75 and opens the first lock to Tourian.
A huge dragon that flies into the air and shoots a stream of fireballs. Attack it with missiles to defeat it. Defeating Ridley increases Samus's missile capacity by 75 and opens the second lock to Tourian.
A huge super computer that controls the Space Pirates and the Metroids. After destroying its Zeebetite life support system, break open its glass shielding and attack it with missiles to defeat it. Once the Mother Brain is destroyed, it triggers a self-destruct and Samus must race back to the surface of the planet.
A small ball of energy left behind after defeating some enemies. Collect the Energy Ball to restore 5 units of energy to Samus. Stronger enemies may leave behind Energy Balls that restore 20 units of energy.
Adds an extra 100 units of energy to Samus's power meter. Samus can have up to 6 Energy Tanks, and there are 8 hidden on the planet Zebes.
A small missile left behind after defeating some enemies. The Missile item restores two missiles to Samus's supply.
Adds the ability to store an extra five missiles. There are 21 Missile Rockets hidden on the planet Zebes.
A Power Item that allows Samus to activate Morph Ball mode, transforming into a ball that can fit through narrow spaces. The Maru Mari is hidden very near the start of the game.
A Power Item hidden in Brinstar that allows Samus to drop up to three bombs when in Morph Ball mode. The Bombs can be used to break blocks or bounce Samus higher.
A Power Item hidden in the Brinstar area that increases the distance Samus can fire the Beam weapon to the full length of the screen.
A Power Item that changes Samus's Beam weapon, allowing it to freeze enemies. Samus can then use the frozen enemies as temporary platforms.
A Power Item that improves the strength of Samus's Beam weapon. As well as more power, the Wave Beam can travel through solid matter. However, it is ineffective against Metroids.
An enhancement to the Power Suit that halves the amount of damage Samus receives from enemies and lava. Hidden in Brinstar.
A Power Item that allows Samus to jump 1.5 times higher than usual. Hidden in Norfair.
A Power Item that transforms Samus's spinning jump into a devastating spin attack, destroying many enemies on contact.
