This was the theme of the first area you begin in.

After you awaken, you can basically go anywhere you wanted, including straight to the end of the game if you knew where the secret entrance there was.

But normally, you'd head down a few hallways, and could choose to enter the upper area and collect your first alternate weapon, or head down and collect the first non-weapon upgrade. It was an item that behaved sort of like the spider ball from Metroid 2.