Look in one of the lockers in the girl's shower room to find Samus' helmet.
Talk to the guard that took you to get Rouqe's armor. Once you get the armor he will say nothing for a short while, then say "What am I doing here?"
Escaping from ghosts
This trick requires a controller with an auto-fire feature. Set the auto-fire to a button. Every time you get caught by them, just hold a button. This helps when fighting the Boss that takes over Rouqe's body.
How to beat Beating Gigi's brother (first form)
Wait until he shoots a missile at you. Then, get out of you body and possess the missile. Aim the missile toward him. Do this quickly, as the red ghosts will possess you and try to make you kill yourself.
Base Rocket launcher
To get the rocket launcher on the multi-player map "Base", jump boost to get on the skinny platform where a man is standing. Go left from the gun turret to get there.
Look in one of the lockers in the girl's shower room to find a Gamecube.
How to beat the stone golems
Shoot the pieces of stone that are glowing. After you have shot all of the pieces, keep grenading him with the secondary fire of your gun that you have.
At the part were you scare the three scientists, the one you possess determines which weapon you will get. To get one of them, have a host knock on the door.