Acquire a Chaos Emerald.

Finish one match of Gotham City Impostors.

Killing 100 enemies with the blade launcher.

Complete any Sector on the Hard difficulty setting.

Complete any Sector without firing a single shot. (Hint: Use the Charge Attack!)

Defeat the final Boss.

Defeat 10 enemies or more using one Laser shot.

Complete your first level in Arcade mode.

Point out a special enemy using the "shout out" command.

Defeat 20 enemies with hand-to-hand combat

Use each weapon one time.

Complete your first Sector.