In the original game, this room is a straightforward corridor, identical to two other corridors in Brinstar, all of which consist of blue pipes. Patches of green bushes line the floor. Both doors are positioned on metal walkways, raised above the floor by a single pillar each.
The remake Zero Mission expands the room and implements a navigation puzzle. The corridor is now constructed out of solid blue metal or other material, with small sections of natural rock found near the exit and in the floor. The room is partially filled with a pool of acid, which is corrosive to the touch without the Varia Suit. When Samus enters the room, she finds two Tangle Vine Fruits in the way. Parasites will automatically drop to the left of the fruit and destroy them both, clearing a path for Samus. Touching the fruit with the Parasites attached to her will cause them to eat the fruit until it explodes, clearing a path.
A roughly "W-shaped" group of pillars and platforms is found above the acid, with a Pit Block in between each pillar. Samus must make use of her Power Grip and Morph Ball to safely navigate this until she drops to a smaller platform above the acid. From there are three additional blocks in midair, which are Pit Blocks that crumble after a second of being stood on. Samus must quickly jump across these and to a ledge above, then lay a Bomb to destroy a line of blocks. These drop additional Parasites to the left, which quickly devour another Tangle Vine Fruit. Samus can then proceed to collect the Varia Suit. Should she fall into the acid, there are steps on the right side that will allow her to climb out. Once she has the Varia Suit, she can safely drop into the acid and leave the room through the pool.
- 5 Reos (Metroid; 3 green, 2 red)
- 5 Zoomers (Metroid; 4 yellow, 1 red)
- 2 Tangle Vine Fruits (Zero Mission)
- Parasites (Zero Mission)
- Energy Tank (Zero Mission)
- Requires Varia Suit. Samus must drop into the acid lake when she has the Varia Suit, and lay a Bomb in the floor between sections of rock. This will expose a tunnel leading left, at the end of which is this tank. It can be obtained before the Varia Suit is acquired, but without it Samus will take damage from the acid.
- 120 WATCH THEM WITHER (pg. 55)
- "A pair of living barriers blocks the path left. Stand close to the right barrier and watch as a group of parasites eats through both barriers on its way to you. Roll along the floor to gather up the parasites, then destroy them with bomb blasts."
- 121 MORPH BALL HOP (pg. 55)
- "As you continue your run to the left, jump and roll into the path near the ceiling. When you fall between columns, you'll land on a breakaway block. Hop up and roll left before you fall into the acid. When you reach the solid barrier, hop and bomb a block to set off a chain reaction that will open a hole to the left."
- 122 TRANSFER PARASITES (pg. 55)
- "You'll find another living barrier outside of the room that holds the Varia Suit. The parasites in the area will naturally gravitate toward the barrier, but you can help them along by picking them up and rolling close to it. They'll transfer over to the pulsing organism and devour it."
- 124 energy tank (pg. 56)
- ""The protection of the Varia Suit will allow you to explore the depths of acid pools. Drop into the acid on your way out of the area and bomb the floor. You'll discover a blastable path to the left that will take you to an Energy Tank."