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.
"Mother's embrace" completed
Completed "Prey" on Normal difficulty
"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
"Guiding Fires" completed
"There Are Others" completed
"Sacrifices" completed
"Crash Landing" completed
"All Fall Down" completed
"Second Chances" completed
"Rites Of Passage" completed
"Downward Spira"l completed
"Escape Velocity" completed
"Last Call" completed
Scored over 15,000 on Runeman
$250 won on Black Jack
$250 won on Draw Poker
Score 25 Sniper kills in Multiplayer
Score 25 Wrench kills in Multiplayer
Reached 25 Rifle kills
Score 25 Crawler Grenade kills in Multiplayer
Score 25 AutoCannon kills in Multiplayer
Score 25 Crawler Launcher kills in Multiplayer
Score 25 Leech Gun kills in Multiplayer
Complete "Prey" on Cherokee difficulty
Score over 50 kills in Death Match
Score over 125 kills in Death Match
Score over 250 kills in Death Match
Score over 50 kills in Team Death Match
Score over 125 kills in Team Death Match
Score over 250 kills in Team Death Match
Score 25 Spirit Form kills in Multiplayer
Score 25 Acid Sprayer kills in Multiplayer
Win a Ranked Multiplayer Match
Play ten Ranked Multiplayer Matches