Full list of all 50 Legendary achievements worth 1,000 gamerscore. It takes around 60-80 hours to unlock all of the achievements on Xbox 360.
Won 50 ranked Multiplayer matches
Was first place in kills in 10 ranked Multiplayer matches in a row
Ranked 4x4, max Animus match: filled 25% of machine, killed 10 players, 10 werewolves, won match
Filled 50% of your team's Monster Machine with Animus in a ranked 4v4 Multiplayer match
Survived a ranked 4v4 Multiplayer game without being killed
Killed 10 enemy players in a ranked Multiplayer match without being killed
Looked at all "The Great Langtini" posters littering Times Square in Episode 3
Ran all Council Base lab experiments in Episode 6
Fired every weapon available in any ranked Multiplayer match
Started and finished a ranked Multiplayer match
Killed 10 Werewolves in a ranked Multiplayer match without being killed
Bypassed the electronic lock in Episode 1
Chopped your way out of the Internet Café with the Fire Axe in Episode 1
Created a ramp with the soda machine using your pistol in Episode 1
Extinguished the doorway fire using the water valve in Episode 1
Completed Episode 1
Unlocked the warehouse exit in Episode 2
Found the Black Order-eliminating electric switch in Episode 2
Completed Episode 2
Was stepped on by the Giant Golem in Episode 3
Escaped the Nari-possessed vending machine room in Episode 3
Destroyed the Giant Golem in Episode 3
Completed Episode 3
Destroyed a Blood Spider Queen in Episode 4
Defeated the first Alpha Werewolf in Episode 4
Eavesdropped on the Black Order as they caged up a Werewolf in Episode 4
Completed Episode 4
Defeated the Minotaur in Episode 5
Caused Minotaur to destroy all Graveyard wall sections in Episode 5
Defeated the Griffon in Episode 5
Completed Episode 5
Shot down the low flying Griffons in Episode 6
Completed Episode 6
Caused the crane to drop the metal beams in Episode 7
Took out the power to the Black Order outpost in Episode 7
Completed Episode 7
Survived the double Minotaur attack in Episode 8
The Lead Designer apologizes for writing the terrible pun "DouBull TrouBull" - have some points
Freed Vivian from captivity in Episode 8
Completed Episode 8
Completed game on Easy difficulty
Killed 25 enemies with the Fire Axe in Single Player
Used the Animus Pulse ability 10 times
Changed the frequency of an Aniform Control Device in Single Player
Complete game on Normal difficulty
Complete game on Hard difficulty
Collect 1/2 of PDA pick-ups
Collect all PDA pick-ups
Fire all 8 projectile weapons in Single Player at least once
Play 200 ranked Multiplayer matches