The debut gameplay trailer for Batman: Arkham City was released on March 15, 2011. 

In the trailer, Catwoman is being held prisoner by former District Attorney Harvey Dent, a.k.a Two-Face, and it is up to Batman to save her. The Joker's underling, Harley Quinn, also makes an appearance in the trailer, and Batman is seen beating up a variety of thugs and goons.

Arkham City is a much larger game world than that of the series predecessor Arkham Asylum. The combat and stealth mechanics return in this second release, but there is more of a focus on the game's puzzle and exploration elements. The trailer also demonstrates some examples of how Batman will make use of flight with his cape will work in the game. 

All of the gadgets earned during gameplay of Batman: Arkham Asylum will be playable at the outset of Arkham City, including smoke bombs, cryptographic sequencer used to hack into communications between master criminals and their underlings, bat claw and line launcher, and the broadcast tracer device that pinpoints the source of signals when tracking.http://xbox360.ign.com/articles/115/1154717p1.html Some of the weapon gadgetry has been enhanced. Explosive gel, used to break down walls in Akham Asylum, is now an integral part of the combat system.

The original game's stealth elements are also preserved, and the in-game combat system has been improved.http://www.gamespot.com/events/msshowcase2011/story.html?sid=6300792&tag=newsfeatures;title;3&pid=981374  The game is also said to include more puzzle elements than the series original. Detective mode, for example, has been developed into an "augmented reality mode" that is used to perform forensic analysis at crime scenes.http://www.gamespot.com/events/msshowcase2011/story.html?sid=6300792&tag=newsfeatures;title;3&pid=981374  Batman also has access to a criminal database to track major villains within Detective Mode. 

However, in this release, the trophies hidden by Riddler throughout the city will require more effort to locate. They may be surrounded by traps, or require interrogation of Riddler's men.http://xbox360.ign.com/articles/115/1155675p1.html 

The events in Arkham City take place approximately one year after those played through in Arkham Asylum.  Quincy Sharp, the former warden of Arkham Asylum, took credit for taking care of the Joker and parlayed that into becoming the mayor of Gotham City. After he takes office, Sharp purchases large sections of the city's slums and arms the perimeter with private military contractors. This maximum security area is christened Arkham City, a plot of land much larger than Arkham Asylum. 

Prisoners are allowed to roam Arkham City at will, as long as they do not attempt an escape. Each of Batman's archenemies controls one district within the massive open game world. Batman watches over Arkham City, concerned that the situation will quickly deteriorate. The game begins when Two-Face hatches a plan to assassinate Catwoman. Batman enters Arkham City to stop her execution.

In addition to the main story line, players will complete side missions that feature key game characters and their secondary story lines.