Full list of all 62 Batman: Arkham Origins achievements worth 1,300 gamerscore. It takes around 40-50 hours to unlock all of the achievements in the base game.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 2 DLC packs containing 12 achievements worth 300 Gamerscore.
Finish I Am The Night Mode
Complete New Game Plus
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)
Obtain all the medals on Custom maps in Challenge mode
Obtain all the medals on Combat Training maps
Collect every collectible
Collect all Enigma items
Complete all Most Wanted missions
Use every Freeflow Focus gadget in one combo
Acquire all upgrades
Hear everything Alfred has to say
Complete all Casefiles
Use the Batwing to travel to all Fast Travel points
Defeat the Joker
Capture all of Black Mask's Assassins
Complete all Dark Knight challenges
Master the Worst Nightmare Dark Knight track
Master the World's Greatest Detective Dark Knight track
Save a life
Master the Gotham Protector Dark Knight track
Master the Shadow Vigilante Dark Knight track
Successfully battle Shiva without taking any damage
Find the Black Mask
Take down 100 enemies who didn't know you were there
Scan 20 Anarky Tags
Who is the Joker?
Stop 20 Crime in Progress
Decipher one Extortion File
Glide 26 miles total
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
Reach x50 Combo
Glide across Bridge without touching ground
Shut down an entire Tower Network
Identify Black Mask's assassins
Win a round of each map with each faction in multiplayer
Take down 6 different Elites in a match, using 6 different methods as Batman or Robin in multiplayer
As a Hero, defeat 4 Elites within 40 seconds without using melee in multiplayer
Defeat each of the enemy players at least once in a multiplayer match
Earn a level of prestige in multiplayer
Reach max level with the Joker faction in multiplayer
Reach max overall level in multiplayer
Reach max level with the Bane faction in multiplayer
Fully upgrade a weapon in multiplayer
As an Elite, earn 4000 XP in a single multiplayer match
Kill a Hero to bring back your entire gang when at 0 reinforcements on a full multiplayer server
Obtain all 108 medals on the original Arkham Origins campaigns (as Bruce Wayne)
Obtain all 72 medals on the original Arkham Origins ranked maps (as Bruce Wayne)
Free all civilians frozen in cryogenic ice
Stop Freeze and bring Boyle to justice
Perform 3 ice wall takedowns
Takedown 2 enemies with one stalactite
Stop Anarky thug operations in South Gotham
Assemble the cryonucleation tunneller - the cryodrill
Find all Activist tags
Receive the Extreme Environment Suit (XE Suit)
Get 3 enemies frozen in one attack
Take no damage when playing as Bruce Wayne