Here is the full list of all 49 Conan achievements worth 1,000 gamerscore. It takes around 20-25 hours to unlock all of the achievements on Xbox 360.
Impale 100 enemies
1000 dismemberments
Complete the game on King mode
Find all treasure chests
Score 100000 total points
All two-handed blade attacks mastered
Combo Counter reaches 325
Combo Counter reaches 100
Kill 100 enemies by boulder throw
Complete a mission without taking any damage
Complete the game on Hard mode
Send Graven into the Netherworld in the Ocean Ruins and complete the game
Activate all rune triumvirates
Find all Song of Death meter powerups
Save all maidens
Find all Power Meter powerups
Find 50 treasure chests
Collect all armor pieces
Defeat the Bone Cleaver in Argos and obtain The Ward of the Departed
Kill 10 or more enemies simultaneously
200 parry kills
All dual wield attacks mastered
Disarm 100 enemies
Find all Health Meter powerups
500 dismemberments
Defend the ship and defeat the Giant Squid
500 grapple kills
250 grapple kills
50 Grapple Kills
Kill 100 enemies by death fall
Kill at least 25 enemies during the Giant Squid boss battle
Defeat the Sorceress Queen in Stygia and obtain The Ward of Souls
Kill 5 or more enemies simultaneously
All one-handed blade attacks mastered
Defeat the Elephant Demon in the Kush caves and obtain The Ward of the Abyss
Activate 5 rune triumvirates
Defeat the Sand Dragon in the lost city of Shem and obtain The Ward of the Earth
Disarm an enemy
Score 20000 points in a level
Defeat the Bone Cleaver and his army in Barachan Isles and obtain The Ward of Fire
100 parry kills
100 dismemberments
Perform every parry kill move
Decapitate a captain with a shield
5 Grapple Kills
Impale an enemy
Kill an enemy by death fall
Find 5 treasure chests
Save a Maiden