First, let’s get one observation out of the way: Batman: Arkham City is the best Batman video game since Batman: Arkham Asylum, which at that point was the best Batman game of all time. It is the best simulation of what it should feel like to be the Dark Knight, Gotham’s only hope against hordes of insane criminals. You solve mysteries using cutting-edge gadgets, you swing and glide from the rooftops, and you take on thugs in packs of thirty at a time. It’s like a grown-up version of the 90s classic, Batman: The Animated Series, even featuring many of the same voice actors (Kevin Conroy, Mark Hamill, etc). If you like Batman, get this game.
So that’s the gameplay and the atmosphere. What about the story?
[WARNING: there's no way for me to do justice to this article without spoiling the entire plot of Arkham City, so I'm going to do that now. The game is still playable, and even enjoyable, if you know the entire storyline, but consider yourself warned.]
So: Quincy Sharp, fresh off the success of his stint as warden of Arkham Asylum, runs a successful campaign for Mayor of Gotham City. His first major act is to wall off an entire borough (including a museum and the old police station) and turn it into a giant open air prison. Armed guards patrol the skies in choppers, while Gotham’s master criminals war for territory. Weird psychiatrist Dr. Hugo Strange has been placed in charge of the prison.
(All the above is prologue, by the way, spelled out only through indirect references)
Bruce Wayne holds a press conference calling for an investigation into abusive practices within Arkham City. He’s arrested and thrown inside the walled prison. But this was all a clever ruse to get Wayne inside, where he changes into Batman and sets off on his investigation. Of course, Dr. Strange already knows that Bruce Wayne is Batman, and taunts him privately with this knowledge before boasting that he will soon put “Protocol 10″ into effect.
Batman tracks down the Joker, hoping to learn from him what Protocol 10 is. Joker is dying from the TITAN-enhanced Venom derivative that he used in Arkham Asylum, however. He injects Batman with a sample of his blood in a surprise attack, forcing Batman to hunt down a cure. Mr. Freeze had been working on a cure, so Batman goes to rescue Freeze from Penguin.
Freeze claims that the cure won’t work without a serum derived from blood with regenerative properties. Batman reasons that Ra’s al-Ghul’s blood might work, and trails one of his assassins to a secret hideout. Talia al-Ghul, Ra’s daughter, invites Batman to undergo the “Trial of the Demon” to prove his worthiness to replace Ra’s; Batman accepts, defeats Ra’s, and swipes a sample of his blood.
Freeze uses Ra’s blood to engineer a cure, but Harley Quinn steals the last sample before Batman can take it. Batman fights Joker and his goons, but is pinned beneath rubble as Dr. Strange initiates Protocol 10, bombarding Arkham City with rockets. Joker is about to finish Batman off when Talia appears, offering Joker a chance at immortality. The two of them leave together.
Batman gets free and infiltrates Strange’s tower. He learns that Ra’s Al-Ghul was Strange’s benefactor shortly before Ra’s kills Strange. Strange initiates a self-destruct in the tower control room, forcing Batman and Ra’s to jump out; Ra’s dies in the fall.
Joker sends a message to Batman, saying he’s taken Talia hostage. Batman goes to save her, only for Talia to overpower Joker and kill him. But the Joker she “killed” is in fact Clayface, masquerading as a healthy Joker. The real, TITAN-infected Joker shoots and kills Talia. Batman then defeats Clayface, retrieves the cure from Talia, and ingests enough of it to cure himself. Joker tries to swipe it from Batman, but the vial shatters. Batman carries Joker’s body outside the walls of Arkham City and delivers him to Commissioner Gordon, before returning to the prison to continue cleaning it up.