Enter the Otherworld for the first time.

Complete any special operation on Easy difficulty.

As an Engineer, restore 10,000 armor points to teammates in Co-op or Versus.

Inflict 100,000 damage to enemies.

Reach Silent Hill.

Capture and lock up Harley Quinn

Face your biggest fears and keep your sanity

Gain access to Arkham Mansion after it is locked down by the Joker

Solve 5% of Riddler challenges

Save all the doctors in Medical

Escape from Intensive Treatment to the island surface

Rescue the guards and henchman from the Joker toxin in Decontamination

Complete a combo of 5 moves (any play mode)