Area 51

					


Secret tapes:

Find and scan all five databank items in a level to unlock the secret for that level. The final secret of the game is unlocked when all prior secrets have been found.

Unlock Gray Alien in multi-player mode:

Successfully complete campaign mode under the hard difficulty setting.
Articles :

Before you go to were they faked the moon landing there is a wall of pipes just before the elevator room. There is mutegen and health with alien grenades.