other: agon energy skip
After you get the dark suit, use the dark beam on the light crystal by the entrance and it'll become a nullified crystal (able to stand higher on it). Jump on it, then space jump to the entrance door. Continue the game without collecting/returning Agon's energy.
Notes:
- The energy tank in Mining Plaza can't be gotten until you return the energy (the sonic emitters don't exist). In 100% files, returning is necessary unless you picked up the missile launcher twice.