Gotham Knights Update Adds 4-Player Heroic Assault And 2-Player Showdown Modes Today - Game Informer

Finally, all of the Gotham Knights can fight together.

PvE Mode Heroic Assault and Boss Rush Showdown Added to Gotham Knights - EIP Gaming

4 Players Co-op In Gotham Knights Heroic Assault Part 2!

News - May, 2012

Can you play Gotham Knights with 4 people?

Game Informer - January 2015 USA, PDF, Xbox 360

Batman, Arkham Wiki

Gotham Knights Heroic Assault and Showdown modes update out now

Batman: Arkham Asylum reviews - MobyGames

Music

Gotham Knights Heroic Assault and Showdown modes update out now

The Joker (Arkhamverse), Batman Wiki

Gotham Knights to Get Heroic Assault, a Free Four-Player Co-Op Mode, In November

Gotham Knights' Four-Player Co-Op Mode Heroic Assault Launching November 29