Full list of all 21 Far Cry Classic achievements worth 400 gamerscore. It takes around 10-12 hours to unlock all of the achievements on Xbox 360.
Complete Dam level without equipping a weapon on person (mounted weapons are allowed).
Do not let Valerie die even once in Swamp.
Score 1 kill each from a land, maritime and aerial vehicle.
Complete Treehouse without dying.
Collect the Key card in Research without alerting anybody!
Fall over 150m and survive.
Complete Volcano Mission.
Complete the game in Hard or Realistic difficulty.
Kill the Traitor with a melee attack.
Defeat Krieger.
Complete Swamp Mission.
Kill Crowe with a headshot.
Get a headshot kill from 500m.
Complete Rebellion Mission.
Complete Steam Mission.
In Bunker, make the Mercs and the caged Trigens mingle with each other
Complete Pier Mission.
Run over 5 enemies while driving a vehicle
Do not die while Doyle hacks the entry gates.
Complete a level with full health and armor.
Complete Training mission.