Area 51 cheats and cheat codes for PC

Area 51 (2005)

Final Secret:
Find all the secrets in game to unlock the last secret.

Unlock hard difficulty:
Finish the campaign mode in medium difficulty mode.

Unlock Alien avatar in multi-player mode:
Finish the campaign mode in hard difficulty mode.

Level skip:
Go to the main menu. Choose "Arcade", then aim at the black border 
of the boxes with "Warp Ahead" or "Beginning" to begin farther 
into the game than normal. 

Beat Grays easily:
Use shields, mutate and fire parasites at them.

Endings:
Good End: Shoot all the panels of the mothership
Bad End: If you let the mothership escape

Hidden tapes:
Find and scan all 5 databank items in a level to access to the secret 
for that level. The final secret of the game is unlocked when all prior 
secrets have been found. 

Infrared:
If you start the game, only shoot the first three STAAR team members. 
If you do this right, you will get an infrared sight.


Secret Rooms locations:

Level 2: 
Go to the hangar and shoot all the highest windows in the far wall.
Get in the truck, shoot all yellow barrels.

Level 4: 
Shoot every yellow box while you are driving on the STAAR jeep.

Level 5: Shoot the sign which shows the words General Weatherby on the 
second door right away when this door opens.

Level 7: Shoot all yellow barrels in the first area where the four purple 
zombies are throwing barrels.