Here is the full list of all 70 Batman: Return to Arkham - there are Arkham City achievements worth 1,500 gamerscore.
Rescue the fourth hostage from Riddler
Track down the serial killer
A moment of remembrance
Stop all assaults in Arkham City
Rescue the third hostage from Riddler
All the world is a stage
Don't look down
Steal the score of a lifetime
Fight for survival
Reveal the mystery watcher
Stop the phone booth killer
Destroy it all
Reunite the separated couple
Stop the contract operative
Collect enough evidence to locate the gun for hire
Time is running out
Complete a combo of 50 moves (any play mode, any character)
A deadly game of hide and seek
We are legion
Uncover the secret of Arkham City
Rescue the second hostage from Riddler
Stop the unstoppable
Last man standing
Rescue the first hostage from Riddler
Clear the airwaves
Solve the first riddle
Answer a ringing phone
Find someone to play remote Batarang catch with
Drop in on an old friend
Hammer the point home
There is only one way in
Complete all augmented reality training exercises
Answer the call for help
Save the medical volunteers
Save the damsel, but is she in distress?
Become the Bat
Collect all of Batman's gadgets and upgrades
Rescue the fifth hostage from Riddler
Rescue all the hostages from Riddler
Obtain 24 medals on the original Arkham City ranked maps (as Batman)
Obtain 48 medals on the original Arkham City ranked maps (as Batman)
Obtain all 72 medals on the original Arkham City ranked maps (as Batman)
Obtain 36 medals on the original Arkham City campaigns (as Batman)
Obtain 72 medals on the original Arkham City campaigns (as Batman)
Obtain all 108 medals on the original Arkham City campaigns (as Batman)
Complete one combat challenge without taking damage (any character)
Complete New Game Plus
Jump off the tallest building in Arkham City and glide for 1 minute without touching the ground.
Have 12 murderous dates with Calendar Man
Perform a perfect combo including all of Batman's combat moves (any play mode)
Use 5 different Quickfire gadgets in one fight (any play mode)
Main Story, Side Missions, Upgrades, Collectables, New Game Plus and Riddler's Revenge (as Batman)
Complete all 40 of the Catwoman Riddler grid items
Retrieve your stolen goods
Obtain all 72 medals on the original Arkham City ranked maps (as Catwoman)
Obtain all 108 medals on the original Arkham City campaigns (as Catwoman)
Obtain 78 medals on the original Arkham City and Robin Bundle Pack ranked maps (as Robin)
Obtain 114 medals on the original Arkham City and Robin Bundle Pack campaigns (as Robin)
Obtain 78 medals on the original Arkham City and Nightwing Bundle Pack ranked maps (as Nightwing)
Obtain 114 medals on the original Arkham City and Nightwing Bundle Pack campaigns (as Nightwing)
No crimefighter should be without this
Find a way into the secret base
Clean up the Dry Docks
The joke's on who?
Zip Kick 5 different thugs
Shield Bash 5 different thugs
Snap Flash an unarmed thug, an armed thug, an environmental object and a Titan
Defuse all bombs in 3 minutes or less
Use 5 different Quickfire gadgets in one fight as Robin in Harley Quinn's Revenge
Destroy all Harley Balloons