Completing Area 2

Walkthrough: Once back in the big room, go through the door on the left you could access earlier. Once inside, head to the door on the left to find a smaller lava room and another Ammo Recharge Station. On the door to your right will be an Aeion Recharge Station. After refueling, go to the previous room and keep going down. Enter the door at the far bottom to find another Energy Recharge Station and Save Station. Above the Energy Recharge Station is another Missile Expansion.

From here, go through the door on the right and continue until your reach the two vents. Use your Spring Ball to Bomb the blocks above the vents, and then proceed to the next room. It is here that you'll find another Alpha Metroid. After defeating it, return to the previous room and take the door on the right. After going through the next door on the left, continue to face yet another Alpha Metroid. After destroying it, open the door to your left and enter the next lava room. Get down to the bottom to find the next door, the same that will require a Wave Beam to open. The next Alpha Metroid will be found here.

After defeating it, return to the previous room and enter the door to your right. Break through the number of blocks to find another Teleportation Statue. Break the block between the passageway going up, and then Super Jump to the ledge. Use your Ice Beam to Freeze the enemy that appears directly over the lava, using it as a platform to reach the next door and Alpha Metroid. After destroying it, head back to the last Teleportation Statue to go to the Chozo Seal and finish Area 2. After removing the purple lava like the last two areas, head down until you get to the bottom and reach the next elevator to Area 3.

Missile Expansion 1: In the lower section of Area 2 that contains both a Save Station and Missile Recharge Station, destroy the weak point in the wall above with one of your Bombs. Head all the way to the right and start moving up. Keep Bombing the the ceiling to go higher, heading to the left afterwards to find the Expansion.

Missile Expansion 2: Underneath the Chozo Seal on you way out of Area 2 is a small passageway of the right of the flora, the same that will lead you straight to the Missile Expansion.