Full list of all 44 Prey (2006) achievements worth 1,000 gamerscore. It takes around 15-20 hours to unlock all of the achievements on Xbox 360.
Completed "Prey" on Cherokee difficulty
Completed "Prey" on Normal difficulty
"Mother's embrace" completed
"Facing The Enemy" completed
"Oath Of Vengeance" completed
"Resolutions" completed
"Center Of Gravity" completed
"Ascent" completed
"The Complex" completed
"Following her" completed
"The Dark Harvest" completed
"Jen" completed
"Hidden Agenda" completed
"The Old Tribes" completed
Reached 250 kills total in Team Death Match
Reached 250 kills total in Death Match
Reached 25 Crawler Grenade kills
"Guiding Fires" completed
"There Are Others" completed
"Sacrifices" completed
"Crash Landing" completed
Reached 25 Leech Gun kills
Reached 25 Crawler Launcher kills
Reached 25 Rifle kills
Reached 125 kills total in Team Death Match
Reached 125 kills total in Death Match
Reached 25 Spirit Form kills
Played ten Ranked Matches
Reached 25 AutoCannon kills
"All Fall Down" completed
$250 won on Draw Poker
"Second Chances" completed
"Rites Of Passage" completed
"Downward Spira"l completed
"Escape Velocity" completed
"Last Call" completed
$250 won on Black Jack
Scored over 15,000 on Runeman
Won a Ranked Match
Reached 25 Wrench kills
Reached 50 kills total in Team Death Match
Reached 25 Sniper kills
Reached 50 kills total in Death Match
Reached 25 Acid Sprayer kills