This is a step by step guide on how to beat Metroid. I will guide you to clear the whole game with all items and weapons. I've already listed some information in order.
You got a lot of reading to do.

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I. Story
II. Items
III. Map
IV. Walkthrough
V. Credits
VI. Gallery
VII. Support
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~ Story ~
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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 stellar 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 pirates’
attacks were powerful and it was not easy to catch then in the vastness of
space. The Federation Bureau and the Federation Police called together
warriors known for their great courage and sent them to do battle with the
pirates. These great warriors were called "space hunters". They received
large rewards when they captured pirates, and made their living as space
bounty hunters.

It is now year 20X5 of the history of the cosmos, and something terrible has
happened. Space pirates have attacked a deep-space research spaceship and
seized a capsule containing an unknown life-form that had just been discovered
on the Planet SR388. This life-form is in a state of suspended animation, but
can be reactivated and will multiply when exposed to beta rays for 24 hours.
It is suspected that the entire civilization of R388 was destroyed by some
unknown person or thing, and there is a strong possibility that the life-form
just discovered was the cause of the planet’s destruction. To carelessly let
it multiply would be extremely dangerous. The Federation researchers had
named it "Metroid" and were bringing it back to Earth-- when it was stolen by
the space pirates!

If Metroid is multiplied by the space pirates and then used as a weapon, the
entire galactic civilization will be destroyed. After a desperate search, the
Federation Police have at last found the pirates’ headquarters, the fortress
planet Zebes, and launched a general attack. But the pirates’ resistance is
strong, and the police have been unable to take the planet. Meanwhile, in a
room hidden deep within the center of the fortress, the preparations for
multiplying the Metroid is progressing steadily.

As a last resort, the Federation Police have decided on this strategy: to
send a space hunter to penetrate the center of the fortress and destroy the
Mother Brain. The space hunter chosen for this mission is Samus Aran. Samus
is the greatest of all the space hunters and has successfully completed
numerous missions that that everyone thought were absolutely impossible.
Samus is a cyborg, who’s entire body has been surgically strengthened with
robotics, giving Samus superpowers. Even the space pirates fear this space
suit, which can absorb any enemy’s power. But Samus’s true form is shrouded
in mystery.

The planet Zebes is a natural fortress. Its sides are covered with a special
kind of stone, and its interior is a complicated maze. On top of that, the
pirates have planted devices and booby traps in the maze, and the pirates’
eery followers lie in wait around every corner. Samus has now succeeded in
penetrazing Zebes. But time is running out. Will he be able to destroy the
Metroid and save the galaxy?

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~ Items ~
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Maru Mari Ball

Missile Box - Each pack contains 5 missiles. Be sure to collect them all as you read.

Energy Tank - Adds an extra health bar.

Bombs - You can be able to bomb blocks and go through tiny places.

Varia Suit - Protects you from big hits.

Long Beam - You can shoot further then you can before.

Ice Beam - You can freeze stuff that's in your way. Your gonna need this at the last level.

Wave Beam - A powerful weapon you can use for hard bosses.

High Jump - You can jump to high places.

Screw Attack - This item substantially increases Samus' offensive capabilities. It is an extraordinarily powerful item that turns Samus into a living weapon whenever she spins through the air as she jumps.

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~ Map ~
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As you read this walkthrough, make sure you check the map to see where your going. I know some of you can't read maps with words. For a better view. Click Here!

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Walk Through

Chapter One - The adventure begins -
Brinstar
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So the adventure begins. So for a start off, your gonna need the Maru Mari Ball. Go left, and get the Maru Mari Ball. Go right and go through three blue doors. Go up and go to the first blue door on the right. Go right through the blue door and drop down to the first door on the right. Obtain your first missiles and go left through the blue door. Go up on the first door in the right. Go through five doors. You should be able to obtain your first energy tank. Go up on the first door in the left side. Press Y and shoot your missiles at the red door. Go in and you got your Maru Mari Bombs. Go right through the two doors and drop to the first door in the left. Go left through the blue door and bomb the ground. Then drop to the first door in the left and missile the red door. Fire at the red ball and you now have the ice beam! Go right through the two doors and go all the way up. Then go left. Go through three doors and head up to the door on the right. Go right through the blue door. This is the tricky part. I randomly found this out. Shoot the ceiling and you'll find a passage up above. Be sure to freeze the enemy so he can boost you up. Go left, lay a bomb and quickly turn go into Samus mode and jump. Then go through the left blue door. Go left and blast the red door five times with your missiles and go left. Obtain your Varia Suit and go right through the two doors. Go down and go to the blue door on the right. Go right and obtain your second missile pack and keep going right. Shoot the ceiling, jump and go through the wall. Turn into the Maru Mari ball and bomb up a little through the wall to get the energy tank. Keep going right through the blue door and drop to the second blue door on the left side. Go through three blue doors and go through the blue door on the left side. Jump up to the first door on the left side and blast the red door five times with the missiles. Go through the red door and obtain your LONG BEAM! Go right through the two doors and drop to the second door on the left side. Go into the Maru Mari Ball and go though the tiny pass. When you get the boost jump. Come back here and shoot the ceiling to get the secret energy tank. Go through the blue door and bomb the cracks on the ground. Drop to the right blue door and go down the elevator.

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Chapter Two - Kraid's Lair
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Drop down to the first door on the left. Kill all of the enemies in the room and go to the left. Turn into the Maru Mari Ball and go through the wall. Keep going left and obtain your missile pack. Go right through the blue door and blast the red door. Go right and obtain your missile pack (AGAIN)! Go left and drop to the next red door. Go right and go into Maru Mari Ball and go through the wall. Obtain your energy tank and go left through the blue door. Go into the door on the left side. Keep going left through the blue door. Then drop all the way down and go right through two doors. Keep going right and obtain your missile pack AGAIN! Go left through the door and bomb the ground and go down. Go right through the door. Keep going right and go through the blue door. Bomb the ground and go down. Then go left and your gonna fight mini Kraid. After you killed the mini Kraid. You will receive 75 missiles. Before you leave the room. Go down below the right door into the lava and shoot the wall. You'll find another energy tank. Obtain the the tank and go right. Go through the blue door in the right. Keep going right and go up. Shoot some of the cracks to work your way up. Go to the first door on the left. Go left and obtain your missile pack. Go right and go up to the second door. Go right and go up all the way to the top. Head to the elevator. Congratulations! You beaten Chapter two! Now it's time for Chapter THREE!!!

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Chapter Three - To Norfair
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Once you leave Kraid's Lair, go right. Go all the way up through the cracks and head to the right blue door. Go right and enter the blue door. Go up to the first door in the right and go forward to the next door. Go down the first door on the right and go forward. This is the best part! Enter the door and you get to go down the elevator! W00T! Once you finish the elevator ride. Welcome to Norfair. For a start. Go down and go to the door on the left. Keep going forward through the wall and enter the blue door. Go down and go to the right door. Go forward and obtain your missile pack. Go back and head up to the right door. Go forward and enter to the main entrance. Go right and go forward to the next door. Go up to the first door in the left. Freeze the enemy and jump on top of him. Bomb through the wall and go forward. Blast the red door and enter. Go and obtain your upgrade for your ice beam and turn into the Maru Mari Ball. Go under the item statue and bomb through the wall. Enter the blue door and go up the right door. Go right and bomb through the wall. After that, obtain your two missile packs and go forward. Bomb the ground and head down to the first door on the right. Go forward and obtain the three missile packs. Go back and drop all the way to the second door. Go forward, through the wall and obtain the two missile packs. Go back and enter the blue door. Go into the Maru Mari Ball and bomb the ground. Then drop to the first door on the left. Go forward, blast the red door and enter. And this is where you obtain the High Jump Boost. Go into Maru Mari Ball and go under the statue. Bomb through the wall and go forward. Keep going forward till you get into the green bubble zone. And go up through the ceiling. Go to the right door and blast the red door. Then obtain the Screw Attack. Go back and bomb the ground. Then bomb the ground again and drop to the right door. Go forward, bomb through the wall and enter the door. Once you enter. DON'T MOVE! Go into Maru Mari Ball and bomb the ground. Then go through the lava pit and and enter the left door. Keep going forward, shoot/bomb the wall and keep going forward. Then obtain the energy pack. Go back, through the blue door. Then freeze the enemy at the end of the right of the lava pit. And hop up in the fake lava. Go to the left side of the lava pit and hop up. Then go to the left door. Go forward, through the wall. And enter the blue door. Go left and go forward. Go through the blue door and go in the fake lava pit. Drop down and go right. Go forward and enter the blue door. Then go next to the blue door and bomb the ground and drop to the right door. Go right and obtain the two missile pack. Go back, shoot the ceiling and go to the right door. Go forward through two doors. Then, you should be able to see a lot of piles of crack blocks. Blast through them. Then once you make it to the last pile of cracked blocks. Hop on op of it and turn into Maru Mari Ball. Bomb the cracks and you will find a tiny spot for the Maru Mari Ball! So go through the wall with the Maru Mari Ball! Then keep going right and obtain the missile pack! Go back through the blue. Then go right next to the blue door and bomb the ground. Then drop to the left door. Go forward and blast the red door. Once you enter, you guess it! The wave beam! But don't get too excited. You will only have this weapon for a limited time. Because like I said before on the top of this blog. Your gonna need the Ice Beam for the last level. And we're half way there! So anyway, Go right through the two doors and go up through the fake lava. Go through the left door. Keep going left and enter the blue door. Go left again and keep going left. Once you enter the maze room. Go up and shoot the ceiling. Go up and pass one door and head up to the 2nd door on the right. Go through six doors and drop down to the 1st door on the left. Keep going to left and enter the blue door. Drop down to the right door and enter. Go down the elevator. Now moving on to Chapter four!

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Chapter Four - Ridley's Lair
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Drop down and go left through two doors. Once you open the second door. Don't move and shoot the ceiling. Hop up and jump to the left door. Go forward and obtain your missile pack. Go back and drop down and go left. Once you enter the room. Go to the end of the left side of the lava pit and bomb the ground. Once your under ground. Go all the way to your left and bomb your way out in the end of the trail. Then enter the blue door in the left. Be careful. I suggest you save at the part where you enter the room. There's a secret hole in the ground. Jump over the pit and obtain your energy pack. Drop down and go right through three doors and obtain your missile pack. left and drop down. Go left through two doors and fight Ridley. TIP! Go right next to him and shoot his stomach over a thousand times. Once you beat him, you'll get an upgrade for your missiles and I'm assuming you will receive 75 more missiles. Go left and blast the purple door. Jump on the lava and keep going left. Then hop up the pillar and.... DUH DUH DUH DUUUHHH!!! You got the energy tank. You back through five doors and drop down to the left door. Go all the way to your left and obtain your missile. Go back to your right and enter the blue door. Go all the way up and enter left blue door. Go left and enter the second door. Go up in the elevator. You are now finish with chapter four.

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Chapter Five - Mother Brain
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We are almost done and we're off to get the Ice Beam! Also this is really important! Make sure you have enough missiles. Your gonna need them for the final fight. So go left. Then go up and enter the right door. Go right again and enter. Go all the way up and shoot the ceiling. Go through the 2nd door on the left and enter. Go let again and enter. Go up in the elevator and you are now back to Brinstar. Go past two doors and go up to the first door on the right. Go through three doors and bomb the ground. Enter the blue door on the left and go forward to the next room. And this is where your gonna say good-bye to your wave beam and hello to your ice beam (Again). Go through the two doors and go up through the ceiling. Go left through four doors and go left. Go through the two doors and go all the way up to the top. Enter the left door. Then shoot the two statues and a trail will appear. Go into Maru Mari Ball and go through. Go forward and blast the red door. Then go down the elevator. WEEEEE!!!! You are now entering Tourian. Now you'll might not need my help anymore cause there's not more mazes and secret places you can go. But if you really stink at video games. Then read. Once you go down the elevator. Go all the way down and blast the yellow door with your missiles. Keep moving right and blast the red door. Go all the way down and enter the red door in the left. Keep moving forward and enter the blue door. Now you are going to fight Mother Brain. Warning! This part is really annoying. Your gonna need to avoid the beams and freeze the red circles. Do not kill them or they will come back. Use your missiles and blast the glass and jump over through four pillars. Blast the firth glass in the pillar. Freeze the red circles and jump on top of the pillar. Once your on the pillar. BLAST THE HECK OUT OF HIM WITH YOUR MISSILES. Once you beat him. You have 999 seconds till Tourain blows up. OH CRAP!!! Enter the blue door and keep jumping. Go in the elevator and CONGRATULATIONS! You beaten Metroid!

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Credits
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STAFF

SCENARIO WRITTEN BY
[MAKOTO] KANOH

CHARACTER DESIGNED BY
[HIROJI] KIYOTAKE

[HIROFUMI] NEW MATSUOKA
SHIKAMOTO [YOSHIO SAKAMOTO]

MUSIC BY
[HIROKAZU] HIP TANAKA

MAIN PROGRAMMERS
[HIROYUKI] HAI YUKAMI
ZARU SOBAJIMA
GPZ SENGOKU

N.SHIOTANI

M.HOUDAI

SPECIAL THANKS TO
KEN ZURI
SUMI
INUSAWA
KACHO

HYAKKAN
GOYAKE

HARADA
PENPEN

TOHRYU MAKO*
BENKEI*

CONVERTED BY
[TOHRU] T.NARIHIRO

ASSISTED BY
MAKOTO KANOH

DIRECTED BY
YAMAMOTO [YOSHIO SAKAMOTO]

CHIEF DIRECTOR
SATORU OKADA

PRODUCED BY
GUNPEI YOKOI

COPYRIGHT
1986
NINTENDO

The End

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Gallery
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Samus


Ridley


Kraid


Mother Brain

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Support
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Please let me know if there's any typos or any other mistakes. Thank you!

I hope this blog was helpful and I hope you enjoyed Metroid. Available in the eShop NOW!

Upcoming walkthrough!

This is my next game I'm going to get. Once I get it and beat the game. I'll think about making another walkthrough.

Thanks for reading!