Hint: Door password:
One of the doors on the first floor requires a password. The password could either be "VAMPIRE" or "MANKIND". You can find out the password by solving a puzzle on the first floor.

Hint: Endings:
To get the good ending, pick up the Leila gun in the corridor before the Hanger just when you save her from the zombie. If you want to see the bad, ending leave the gun alone.

Hint: Absorbing enemies:
Your left hand has to the power to absorb enemies, launch attacks, and recover. However, you have a limited supply of energy. You have to absorb enemies to regain the magic. Most enemies only need two hits then you press Square, and they will glow black then fly into your hand, absorbing them.