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 die while Doyle hacks the entry gates.
Complete Treehouse without dying.
Do not let Valerie die even once in Swamp.
Complete the game in Hard or Realistic difficulty.
Collect the Key card in Research without alerting anybody!
Defeat Krieger.
Kill the Traitor with a melee attack.
Complete a level with full health and armor.
Kill Crowe with a headshot.
Complete Training mission.
Complete Pier Mission.
Complete Steam Mission.
Complete Rebellion Mission.
Complete Swamp Mission.
Complete Volcano Mission.
Run over 5 enemies while driving a vehicle
Fall over 150m and survive.
Get a headshot kill from 500m.
Score 1 kill each from a land, maritime and aerial vehicle.
In Bunker, make the Mercs and the caged Trigens mingle with each other