Backtracking After Area 6

Walkthrough: After obtaining the Power Bomb, you can return to many of the previous Areas to find and obtain a number of collectibles. Make sure you backtrack and get them so you don't miss out!

Super Missile Expansion (Surface Area): Head to the cliff to the left of your gunship. Once on the other side of it, Power Bomb the weak pot on the left wall. From there, head inside and use your Screw Attack to drop through the hole. Grab the Expansion on your right.

Super Missile Expansion (Area 6): Use your Screw Attack to break through the walls on the left of the upper left section of Area 6. Bomb the weak spots to reach the red crystals, and then use your Spider Ball on the left wall. Detonate a Power Bomb to blast all the crystals to your right, pulling on the red orb that will show to get the Expansion.

Super Missile Expansion (Area 6): In the lower sections of Area 6, Bomb the weak points on the right wall. From there, use a Power Bomb to destroy the weak points near the vent you'll see. Pull the red orb and then go down, Bombing the first weak spot you find. Activate your Phase Drift, hang on the ledge to your right, and then shoot a Missile at the second weak spot. Head through and roll past the rubble, ultimately ending up falling down below. Use your Screw Attack through the center to reach the Expansion.

Aeion Tank (Area 5): Go to the large room and use your Power Bomb to open the door being blocked by a yellow barrier on the right. Once inside, use your Lightning Armor to get past the flora and reach the Aeion Tank.

Power Bomb Tank (Area 2): Use your Power Bomb to bring down the yellow barrier blocking the door in the second lava section of Area 2. Once inside the door, use your Grapple Beam on the blue orb and then activate your Phase Drift. Run across the breakable floor, and then use your Screw Attack to destroy the wall and ceiling to reach the Tank.

Power Bomb Tank (Area 3): Go to the Aeion Recharge Station on the right side of Area 3. Turn on your Lightning Armor and head through the flora, placing a Power Bomb at the very end to find the Tank.

Power Bomb Tank (Area 5): Head to the Large Room in Area 5 and enter the door at the very top of it. Come to the door will the red crystals, and then use your Grapple Beam to reach the right side. From there, Spider Ball onto the blue block. Use your Power Bomb in that very spot to get blasted to the left, which is where you will find the Tank.

Power Bomb Tank (Area 5): Ride the left elevator down, and the enter the small hallway in the top right corner. Reach the top, and then use your Phase Drift in the connecting two rooms. From there, use a Power Bomb to open the last door and reach the Tank.

Power Bomb Tank (Area 6): Open the yellow barrier door with your Power Bomb found near the spot you fought the Zeta Metroid. Head inside and Bomb the weak spots below you. Destroy the second weak point on the right with a Super Missile, and then pull on the red orb to find the path that leads to the Tank.