Full list of all 44 BlackSite: Area 51 achievements worth 1,000 gamerscore. It takes around 20-25 hours to unlock all of the achievements on Xbox 360.
You finished first in a ranked match containing a Blacksite Virus Carrier
You completed a ranked match of Team Deathmatch
You won your first ranked match
You played in a game with a Blacksite Virus Carrier
You competed in your first Xbox LIVE game of Blacksite
You collected 25 Dossiers
You completed Episode 3: Rachel
You got 5 kills with the Scatter Gun’s bouncing projectiles in Campaign
You got the squad to High Morale more than 20 times
You completed Episode 2: Quarantine
You got more than 10 head shot kills with the pistol in Campaign
You completed Episode 1: Iraq
You got 10 kills while the M4 was equipped in Campaign
You collected a Dossier
You got 5 kills while the Sniper Rifle was equipped in Campaign
Complete Episode 4: Counter Insurgency
Complete Episode 5: Topside
Complete Episode 6: Wrecked
Complete all episodes on Yellow (easy) difficulty
Complete all episodes on Orange (medium) difficulty
Complete all episodes on Red (hard) difficulty
Bring down a Spore Tower
Bring down a Fire Brute
Kill more than 25 Drudge using only melee
Kill more than 250 Reborn
Get the squad to help you get more than 250 Focus Fire Kills
Collect all Dossiers
Get more than 10 kills using the Antitank Launcher's target-lock in Campaign
Get more than 10 kills by detonating the Plasma Rifle's projectile in Campaign
Get more than 100 kills with each weapon
Get more than 200 kills with each weapon
Get more than 400 kills with each weapon
Host an Xbox LIVE game of Blacksite versus (any game type)
Complete a ranked match of Deathmatch
Complete a ranked match of Abduction
Complete a ranked match of Capture The Flag
Complete a round of every Xbox LIVE Ranked Match game type
Win a round of every Xbox LIVE Ranked Match game type
Capture your first flag
Capture more than 25 flags
Capture more than 50 flags
Win more than 25 ranked matches
Win more than 50 ranked matches!
Get over 20 kills without dying in a single Versus match!