Backtracking After Area 1

Walkthrough: After finishing Area 1 and obtaining new weapons, you may want to return to the Surface Area to access areas you previously couldn't to obtain more items. The Spider Ball Ability will let you climb the giant wall just beyond the gunship; however, unfortunately, you STILL won't be able to access the collectibles there. Instead, you'll only be able to complete a few more Missile Expansions.

Missile Expansion 1: To the left of the Teleportation Station, Bomb the block and head inside. Bomb the ensuing wall to create a path that will lead straight to the next Expansion. Use the Spider Ball to climb to it.

Missile Expansion 2: Drop down the hole to the right of the Teleportation Station, rolling all the way to the right after you do. Take out any enemies with your Bomb, and then use your Spider Ball to climb to the Expansion.