Full list of all 60 Batman: Arkham Origins achievements. It takes around 80-100 hours to unlock all of the achievements in the base game on Windows.
The base game contains 50 achievements, and there is 1 DLC pack containing 10 achievements.
Take down 6 different Elites in a match, using 6 different methods as Batman or Robin in multiplayer
Reach max level with the Joker faction in multiplayer
Reach max level with the Bane faction in multiplayer
Reach max overall level in multiplayer
Kill a Hero to bring back your entire gang when at 0 reinforcements on a full multiplayer server
Win a round of each map with each faction in multiplayer
As a Hero, defeat 4 Elites within 40 seconds without using melee in multiplayer
As an Elite, earn 4000 XP in a single multiplayer match
Fully upgrade a weapon in multiplayer
Earn a level of prestige in multiplayer
Defeat each of the enemy players at least once in a multiplayer match