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