Batman: Arkham Asylum - Achievement List
There are 47 achievements with a total of 1000 points.


Big Bang: Complete story mode on Easy difficulty (50 points)
Bigger Bang: Complete story mode on Normal difficulty (50 points)
Biggest Bang: Complete story mode on Hard difficulty (50 points)
Party Pooper: Time to break up this party (10 points)
Freeflow Combo 20: Complete a combo of 20 moves (any play mode) (10 points)
Freeflow Combo 40: Complete a combo of 40 moves (any play mode) (10 points)
Night Glider: Glide continuously for over 100m (5 points)
Rope-A-Dope-A-Dope: String up one henchman and drop him to surprise a second (any play mode) (10 points)
Mano-A-Mano: Take on a beast in hand to hand combat (10 points)
Catch!: Catch a Batarang (any play mode) (5 points)
Freeflow Combo 5: Complete a combo of 5 moves (any play mode) (5 points)
Freeflow Combo 10: Complete a combo of 10 moves (any play mode) (5 points)
Freeflow Perfection: Perform a perfect combo including all of Batman's combat moves (any play mode) (10 points)
Freakshow Rodeo: Ride a beast and unleash its power (10 points)
Freeflow Bronze: Achieve 8 medals on combat challenges (10 points)
Freeflow Silver: Achieve 16 medals on combat challenges (25 points)
Freeflow Gold: Achieve 24 medals on combat challenges (50 points)
Predator Bronze: Achieve 8 medals on predator challenges (10 points)
Predator Silver: Achieve 16 medals on predator challenges (25 points)
Predator Gold: Achieve 24 medals on predator challenges (50 points)
Invisible Predator: Complete one predator challenge by using only Silent Takedowns and without being detected (10 points)
Flawless Freeflow Fighter: Complete one combat challenge without taking damage (10 points)
Crack The E Nigma: Solve every riddle on the island (20 points)
Arkham Analyst: Solve 5% of Riddler challenges (20 points)
Cryptic Investigator: Solve 10% of Riddler challenges (20 points)
Lateral Thinker: Solve 25% of Riddler challenges (20 points)
Mystery Solver: Solve 40% of Riddler challenges (20 points)
Conundrum Cracker: Solve 55% of Riddler challenges (20 points)
Mental Athlete: Solve 70% of Riddler challenges (20 points)
Riddle Resolver: Solve 85% of Riddler challenges (20 points)
World's Greatest Detective: Solve Arkham's biggest mystery (20 points)
Perfect Knight: 100% Complete (75 points)


Secret Achievements:
 

Shocking Rescue: Take down Zsasz in the Patient Pacification Chamber (10 points)
Leave No Man Behind: Rescue the guards and henchman from the Joker toxin in Decontamination (10 points)
Malpractice Needs More Practice: Survive the onslaught from the deformed Joker henchman (10 points)
Born Free: Escape from Intensive Treatment to the island surface (10 points)
Just What The Doctors Ordered: Save all the doctors in Medical (10 points)
Daydreamer: Survive the nightmare of the Scarecrow's fear gas (10 points)
Baneful Payback: Defeat Bane (25 points)
Breaking And Entering: Gain access to Arkham Mansion after it is locked down by the Joker (10 points)
Recurring Nightmare: Face your biggest fears and keep your sanity (10 points)
Zsasz Cut Down To Size: Save Dr. Young from being killed by Victor Zsasz (10 points)
Solitary Confinement: Capture and lock up Harley Quinn (25 points)
Double Trouble: Defeat two Titan Henchmen at once (25 points)
Resist The Fear: Conquer the effects of the Scarecrow's fear gas (50 points)
Crocodile Tears: Venture into Killer Croc's lair and come out alive (50 points)
Poisoned Ivy: Defeat the giant Titan Ivy plant (50 points)


The Official Batman: Arkham Asylum FAQ - Eidos Forums
Xbox360Achievements.org - Batman: Arkham Asylum Achievement List