Drop in on an old friend

There is only one way in

Save the damsel, but is she in distress?

Complete story mode on Normal difficulty

KO all the henchmen celebrating your arrival at the party

Solve every riddle on the island

Defeat the giant Titan Ivy plant

Ride Titan henchman and knock down 10 thugs (any play mode)

Solve 70% of Riddler challenges

Defeat two Titan Henchmen at once

Capture and lock up Harley Quinn

Save Dr. Young from being killed by Victor Zsasz

Complete a combo of 10 moves (any play mode)