West Elevator

Walkthrough: Use the Teleportation Statue to reach the west side of Area 3, running back to the first Elevator you passed when first arriving in Area 3. This elevator will lead to other sections that contain the remaining six Metroids. Once off the Elevator, head downward until you come to a door on your left. There is an Alpha Metroid inside that door that can be defeated now or later, as this will also be the path you will use to leave Area 3. Whenever you decide to face it, you will have to defeat it either way.

From there, head down some more until you find a door on your right. Defeat the Gamma Metroid inside the room, and then head into the connecting room. Down below will be the next Teleportation Statue. Obtain it for you map and then return back to the previous spot, using your Grapple Beam to grab the red block nearby to reach the next door and enter. Going down from there will lead you to the next Missile Expansion, and then start moving up again. Use your Grapple Beam to swing across the area, and then Spider Ball all the way to the top to find another door. Defeat the Alpha Metroid inside, and then Bomb the weak point on the wall. This will lead straight to a door that has lava inside.

Use your Spider Ball to cling to the ceiling to avoid the lava, eventually coming to a weak spot in the floor down below that can be Bombed to reach another room. In said room will be another weak spot in the floor, so go through and then cling to the ceiling. From there, Bomb the section of the platform that just barely touches the lava in order to get through. Continue down this path to find and battle another Gamma Metroid.

After defeating those waves of Metroids, return to the door you passed not too long ago. Head inside to find an Energy Recharge and Save Station. In the following room, use your Grapple Beam to grab the red orb to reveal a giant mechanical beast. This is Diggernaut, one of the Bosses found within the game. Diggernaut is incredibly hard to defeat, but don't worry, you actually don't have to fight it just yet. Enter the next room, and then head to and through the door below.

Start heading down the bottom of the tall room. On the way down is another Aeion Recharge Station, as well as a number of collectibles that cannot yet be obtained. At the bottom of the room, open the door that requires a charged attack. Inside is a Save Station, and below it will be another door. Go through the basically empty room it leads to to reach the next door. In this room, there will be a weak spot on the right wall that leads to what looks like a Metroid Room. Pass this for now and Bomb the bottom left corner to reveal a hallway to the next room. Bomb the weak point in the left wall of this empty room and continue into the room above to find the Gamma Metroid.

After finishing off the Metroid, the same that will jump from room to room as you battle it, head back to the last Save Station. From there, head upward in the tall room to find another Teleportation Statue. Spider Ball up the wall, and use your Grappling Beam to reach the next Missile Expansion. Head through the door on the left that needs a charged shot to be opened. This will lead to another tall room, one with two Missile Expansions; unfortunately, however, you will only be able to get one right now.

Go to the door you will eventually find on your left, dropping down into the water before rolling up to the top of the maze. Two weak points will be found here, and Bombing them both will reveal a room above that has the final Gamma Metroid (before last if you saved the first in this section for the end). Defeat it and then head back to the room with the water, heading through the door to your left. Head back up to the door that leaves this area, killing the original Metroid if you chose to bypass it at first. Enter the following room to reach the Elevator that will lead you to a door that brings you back to the start of Area 3, as well as another Missile Expansion.

Return to the Chozo Seal and stand on the button with the Metroid DNA you have obtained, which will drain the purple lava per usual. Drop down after it does and enter the door on the left. Dropping down the steps instead of going through the passageway will bring you to another door, one that leads to a Missile Expansion. From there, go through the door and break the weak spot with a basic missile. Go up if you want another Missile Expansion, otherwise head to the bottom door to reach the elevator that brings you to Area 4.

Missile Expansion #1: Once you enter the area with the Elevator and used your Grapple Beam to enter the new section through what was the red orb, drop down to the bottom of the room. Bomb the weak point to the left of the water to find the Missile Expansion.

Missile Expansion #2: Grapple Beam over the ledge on the left after defeating the third Gamma Metroid. Destroy the two Eggs with your Burst Beam to find the Expansion.

Missile Expansion #3: Enter the small hallway at the top of the tall room. Once your reach the vertical passageway with the sticky walls, shoot a missile upward and then leap in order to use your Grapple Beam. Pull yourself up to find the next Expansion.

Missile Expansion #4: As you move upward through the final tall room that leads to the last Metroid, look for the weak point on the right side of the center platform. Bomb to find the Missile Expansion.

Missile Expansion #5: After defeating the Alpha Metroid found directly off of the West Elevator, enter the door to the left and use the Elevator. Use your Grapple Beam to pull on the red orb to find the next Expansion.

Missile Expansion #6: After draining the purple lava, enter the door and drop down past the passageway to another door. Use your Spider Ball to scale upward, and then Bomb the weak spot you come to. Use you Lightning Armor to make it past ensuing foes, and then use your Grapple Beam to break the glowing red orb. From there, get back down near the door and use the path to reach the final Missile Expansion.