Here is the full list of unlockable achievements in Batman: Arkham Asylum for the Xbox 360, with the secret achievements listed at the bottom.
Arkham Analyst (20) – Solve 5% of Riddler challenges
Big Bang (50) – Complete story mode on Easy difficulty
Bigger Bang (50) – Complete story mode on Normal difficulty
Biggest Bang (50) – Complete story mode on Hard difficulty
Catch! (5) – Catch a Batarang (any play mode)
Conundrum Cracker (20) – Solve 55% of Riddler challenges
Crack The E Nigma (20) – Solve every riddle on the island
Cryptic Investigator (20) – Solve 10% of Riddler challenges
Flawless Freeflow Fighter (10) – Complete one combat challenge without taking damage
Freakshow Rodeo (10) – Ride a beast and unleash its power
Freeflow Bronze (10) – Achieve 8 medals on combat challenges
Freeflow Combo 10 (5) – Complete a combo of 10 moves (any play mode)
Freeflow Combo 20 (10) – Complete a combo of 20 moves (any play mode)
Freeflow Combo 40 (10) – Complete a combo of 40 moves (any play mode)
Freeflow Combo 5 (5) – Complete a combo of 5 moves (any play mode)
Freeflow Gold (50) – Achieve 24 medals on combat challenges
Freeflow Perfection (10) – Perform a perfect combo including all of Batman’s combat moves (any play mode)
Freeflow Silver (25) – Achieve 16 medals on combat challenges
Invisible Predator (10) – Complete one predator challenge by using only Silent Takedowns and without being detected
Lateral Thinker (20) – Solve 25% of Riddler challenges
Mano-A-Mano (10) – Take on a beast in hand to hand combat
Mental Athlete (20) – Solve 70% of Riddler challenges
Mystery Solver (20) – Solve 40% of Riddler challenges
Night Glider (5) – Glide continuously for over 100m
Party Pooper (10) – Time to break up this party
Perfect Knight (75) – 100% Complete
Predator Bronze (10) – Achieve 8 medals on predator challenges
Predator Gold (50) – Achieve 24 medals on predator challenges
Predator Silver (25) – Achieve 16 medals on predator challenges
Riddle Resolver (20) – Solve 85% of Riddler challenges
Rope-A-Dope-A-Dope (10) – String up one henchman and drop him to surprise a second (any play mode)
World’s Greatest Detective (20) – Solve Arkham’s biggest mystery
Here are the fifteen secret achievements you can unlock in the game:
Baneful Payback (25) – Defeat Bane
Born Free (10) – Escape from Intensive Treatment to the island surface
Breaking And Entering (10) – Gain access to Arkham Mansion after it is locked down by the Joker
Crocodile Tears (50) – Venture into Killer Croc’s lair and come out alive
Daydreamer (10) – Survive the nightmare of the Scarecrow’s fear gas
Double Trouble (25) – Defeat two Titan Henchmen at once
Just What The Doctors Ordered (10) – Save all the doctors in Medical
Leave No Man Behind (10) – Rescue the guards and henchman from the Joker toxin in Decontamination
Malpractice Needs More Practice (10) – Survive the onslaught from the deformed Joker henchman
Poisoned Ivy (50) – Defeat the giant Titan Ivy plant
Recurring Nightmare (10) – Face your biggest fears and keep your sanity
Resist The Fear (50) – Conquer the effects of the Scarecrow’s fear gas
Shocking Rescue (10) – Take down Zsasz in the Patient Pacification Chamber
Solitary Confinement (25) – Capture and lock up Harley Quinn
Zsasz Cut Down To Size (10) – Save Dr Young from being killed by Victor Zsasz
