UPDATE: Batman: Arkham Knight has a new "dual play" mechanic, Warner Bros. has confirmed.
This sees the player "switch seamlessly" between Batman and his allies, including Robin, Nightwing and Catwoman in "free-flow combat".
So, no co-op, then, as some took the trailer below to indicate, but exciting nonetheless.
ORIGINAL STORY: A new Batman: Arkham Knight trailer has shown off superheroes Robin, Nightwing and Catwoman.
The video, below, shows Batman working with Robin, Nightwing and Catwoman in what looks like tag-team combat. Developer Rocksteady and publisher Warner Bros. has yet to announce any kind of co-op gameplay, so we assume this is simply tag-team attacks with computer-controlled allies in, perhaps, challenge rooms.
Either that, or at select points during the campaign Batman can work together with one of his partners in crime fighting.
We already know you can play as Harley Quinn as part of a downloadable content challenge maps pack. As Quinn you fight within the Blüdhaven Police Department in a story that takes place prior to the events of Arkham Knight.
And finally, the video confirms mysterious assassin Azrael is in the game, although to what extent we don't know.
Batman: Arkham Knight is due out 23rd June 2015.