The final leg of the journey is through the Metroid-infested halls and shafts of Tourian. Before you can enter, you must defeat both Mini-Bosses, then shoot the two statues, which activates a secret bridge. Then you descend into the realm of the Mother Brain. Make sure that you are armed with the Ice Beam, or your chances for success are slim.
 Accessing Tourian
So you've beaten Kraid and you've beaten Ridley. The time has come to end your mission and bring the assault to Mother Brain directly. In order to do this, you must climb to the top of the long vertical shaft in West Brinstar, and enter through the highest door on the left. As you proceed to the left, you will make short work of the enemies who once plagued you so fiercely in the beginning. At the end you will reach a red door. Blast it open and step inside. Two statues of Ridley and Kraid calmly wait inside. Fire at each statue, and as long as you have defeated each Mini-Boss, they will rise and lock in place. Once both statues have risen, a bridge will form that Samus can only cross as a ball. Beyond the next door lies the elevator that leads to Mother Brain's domain: Tourian.
 Points of Interest
- 1) Here come the Metroids
- Mother Brain has tailored Tourian to be as close to a paradise for the Metroids that she is breeding as possible. As a result, they have free reign over the entire area. And it won't take the Metroids very long to notice your arrival. While they view every moving thing as a potential food source, they are especially attracted to the energy that gets emitted by Samus' Power Suit, and will not hesitate to home in on her and begin feeding. While powerful, the Metroid are fairly simple minded, and become easily stuck on the platform that lie between them and Samus. You can use this to your advantage by running back and forth, causing the Metroids to follow, and eventually clear themselves from the platform due to their own momentum. This sets them up perfectly for you to freeze them with one shot from the Ice Beam. Then destroying them with 5 missiles. Proceed as safely to the bottom as you can. If a Metroid happens to latch on to you, read the note below to learn how to shake them. The door at the bottom is the second and last odd colored door that requires 10 missile shots to open.
- 2) Add in the Rinkas
- In addition to the Metroids that occupy this hallway, you will eventually come face to face with the Rinkas; energy rings that are by products of the Mother Brain's power supply. They appear and move in whatever direction Samus is in at the time of their appearance. They will never change direction once they start moving. Of course, the real threat is the continued appearance of the Metroids. Once you freeze them, whether you destroy them or not is up to you. If you have full energy and missiles, then there isn't much of a reason to blast them with the five missiles necessary to kill them. It's only truly worth your time to kill them if you are in need of more energy or missiles, as they provide super energy and missile drops, resupplying either one by 30 for every one that you pick up.
- 3) Navigating the maze
- At the top of this shaft, you will need to weave back and forth from one platform to the next. Rinkas will pour out from every direction. If they get too annoying, freeze one or two of them for a brief reprieve. Metroids will hungrily wait for you to drop from one platform to the next. Use the same trick as in point 1 to make them swing up to your location and nail them as they fly up. Or run very quickly to the other end, jump down, and turn around and fire before they have a chance to pick up speed. The bottom of this shaft is a little more broken up, but no less dangerous. More Metroids will fly out and attack you simultaneously. Don't start blasting one frozen Metroid with missiles until every other moving Metroid on the screen has been frozen first.
- 4) The final run
- This final hallway is your last chance to restock on energy and missiles before you enter Mother Brain's chamber, and you would be wise to do so. A majority of your energy will be lost, not during the conflict with Mother Brain herself, but on your way to reach her, so make sure you have at least six full energy tanks before proceeding. Powering up is actually quite easy. Simply run back and forth throughout the hallway until you obtain enough energy by defeating Metroids. They will continuously respawn every time you leave one portion of the hallway and return to another. Once you are confident that you have enough power and missiles, proceed through the left door.
- 5) Attack the Mother Brain's food source
- In order to gain access to the Mother Brain, you will first need to blast your way through the five tanks that serve as the Mother Brain's food source, known as Zeebetites. Zeebetites are a self-replicating energy source contained by the tanks. Only concussive blasts can disrupt their replication. Therefore, you must pummel them with as many missiles as you possibly can, as quickly as you can. If you hesitate for even a moment, the replication process will resume, and they will return to their full state again. While you are attempting to destroy them, the cannons that guard the Zeebetites will fire constantly at you, and Rinkas will continue to appear as well. There's not much you can do about the cannon fire except avoid it, but you can freeze the Rinkas in an effort to limit their threat. In fact, you can even use them to create strategic platforms from which you can blast the Zeebetites without interruption.
- 6) Taking on Mother Brain
- Mother Brain isn't going to simply let you walk up to her and demolish her. Her defense systems will be on high alert by the time you reach her. The cannons will be firing and the Rinkas will spawn continuously. Ideally, if you could stand in the place of the last Zeebetite and fire missiles at her all day long, it would be a very short battle. Naturally, the Rinka will home in on your position and try to prevent you from doing that. It would be a wise strategy to freeze them for as long as you can in order to keep them from interrupting Samus. If you happen to get forced into the lava in front of Mother Brain, you'll have a difficult time getting out unless you freeze one of the Rinkas and use them as a platform to get back up. If you have to fall in one direction or the other, it is far better to fall to the right.
- 7) No time for goodbyes
- As soon as you pump Mother Brain with one more missile than she can withstand, she will deteriorate with a loud noise. As soon as that happens, it triggers a self destruct sequence that threatens to blow all of Tourian up, and everything inside of it. Beyond Mother Brain is a hatch that leads to a long vertical shaft to the surface of planet Zebes. While you have plenty of time to reach the top, it will take a fair amount of jump control in order to safely reach the top before the destruction initiates. Don't let your adrenaline get the best of you. Stay calm and focused and choose the jumps that you feel safest with. The sequence of platforms will repeat themselves a number of times before they finally change, indicating that you've reached the top. Assuming you make it in time, you will be treated to the ending of the game. Congratulations. If you don't make it out in time, it will be Game Over, and you'll be forced to start from the top of Tourian again.
- Detaching a Metroid
- If a Metroid hooks its talons into Samus, it will immediately begin to drain her energy and deplete her life support system. You will be unable to fire any weapons, and no amount of running or rolling will shake the Metroid loose. There is only one technique that will work: Bombs. As soon as a Metroid (or Metroids) latches on to you, squat down into a ball, and start releasing bombs. Just laying a bomb or two won't do the trick because the blast has to actually hit the Metroid. So ideally, you want a bomb to pop you up into the air so that you can lay another bomb in mid-air that will strike the Metroid after you land. When a Metroid is fully inside a bomb explosion, it stuns the Metroid long enough to remove it from Samus. But you have to react quickly because it won't take long for the Metroid to recover and latch back on to you. Freeze it as soon as you are able to stand back up.
- Taking a break to refuel
- If after destroying the fifth Zeebetite, you find yourself extremely low on energy and missiles, it would be a good idea to return to the room to the right and begin refueling by hunting Metroids again. The Zeebetites will never return once they've been fully destroyed, so you don't have to worry about repeating your efforts. It's better to leave and return to face Mother Brain with a good supply of energy and ammunition then to launch a dangerous attack when you're already low on supplies.