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.
Defeat the Joker
Reach x50 Combo
Complete a predator encounter without ever being spotted
Glide 26 miles total
Save a life
Find the Black Mask
Who is the Joker?
Glide across Bridge without touching ground
Defeat Deathstroke
Identify Black Mask's assassins
Shut down an entire Tower Network
Decipher one Extortion File
Collect all Enigma items
Collect every collectible
Complete a Most Wanted entry
Capture all of Black Mask's Assassins
Master the Shadow Vigilante Dark Knight track
Master the Gotham Protector Dark Knight track
Master the Worst Nightmare Dark Knight track
Master the World's Greatest Detective Dark Knight track
Complete all Dark Knight challenges
Complete all Casefiles
Stop 20 Crime in Progress
Hear everything Alfred has to say
Obtain all the medals on Combat Training maps
Obtain all the medals on Custom maps in Challenge mode
Acquire all upgrades
Take down 100 enemies who didn't know you were there
Complete a predator encounter using only silent takedowns
Use the Batwing to travel to all Fast Travel points
Successfully battle Shiva without taking any damage
Complete Deathstroke without failing a single counter
Use every Freeflow Focus gadget in one combo
Obtain all medals on the original Ranked Maps in Challenge mode (as Batman)
Obtain all medals on the original Campaign maps in Challenge mode (as Batman)
Scan 20 Anarky Tags
Complete all Most Wanted missions
Complete New Game Plus
Finish I Am The Night Mode
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
Take no damage when playing as Bruce Wayne
Receive the Extreme Environment Suit (XE Suit)
Assemble the cryonucleation tunneller - the cryodrill
Stop Freeze and bring Boyle to justice
Find all Activist tags in Cold, Cold Heart
Free all civilians frozen in cryogenic ice
Stop Anarky thug operations in South Gotham
Get 3 enemies frozen in one attack
Takedown 2 enemies with one stalactite
Perform 3 ice wall takedowns