There are 55 achievements worth a total of 1260 points
Found all Templar Chronicles
Found all collectible outfits in the game
Found all collectible weapons in the game
Discovered all chests in a single level
Completed all Bonus Objectives in a single level
Completed all Bonus Objectives on all levels
Disarmed a bear trap
Saved your partner from a dog attack
Destroyed a breakable wall
Advanced a character to 5 Health Orbs
Advance a character to 5 Zeal Orbs
Used the "Revive" action to help your teammate
Completed all levels on Normal or higher difficulty
Completed all levels on Hard difficulty
Discovered with a clue
Completed all levels on Casual or higher difficulty
Healed your partner
Acquired all Charge skills for Celian
Acquired all Dagger throw skills for Marie
Killed an enemy grabbed by the other character
Killed all opposing squads with a siege weapon
A fleeing enemy was killed with a siege weapon by you or your partner
Finished a level in an online multiplayer game
Finished all levels in the campaign in multiplayer online mode
Completed 5 levels in online multiplayer with different partners
Hit 4 enemies at the same time with your Charge Attack
Hit 4 enemies at the same time with your All-around Attack.
Played in an online multiplayer game with one of your Xbox LIVE friends
Finished a whole level without both characters dropping below 1 Health Orb
Smashed 5 enemy shields
Finished 30 fallen enemies
Stealth killed a noise distracted enemy
Killed an enemy by knocking him from a ledge
Won a duel
Set 50 objects on fire
Performed 50 stealth kills
Killed 5 enemies in less than a minute without taking damage
Succesfully performed 10 countermoves
Successfully tracked 20 trails to their end
Killed 20 enemies with a ranged attack
Rescued the messenger of King Philip
Completed the Arena (DLC: The Arena)
Completed all Bonus Objectives in the Arena (DLC: The Arena)
Killed 15 opponents in the Arena using Cyclone Strike. (DLC: The Arena)
Completed the first round in the Arena without taking damage (DLC: The Arena)
Completed the second round in the Arena without taking damage (DLC: The Arena)
Completed the third round in the Arena without taking damage (DLC: The Arena)
Survived the siege of Acre
Defeated Muzafar
Explored the Temple of the Nine
Defeated the Beast
Rescued Marie d'Ibelin
Survived the events of Friday the 13th
Found the Grail