In developing Arkham City, Rocksteady Studios in London systematically attacked every aspect of the previous game that was holding it back from greatness and made those solutions into strengths. For instance, two years ago I said of Arkham Asylum, “The entire game takes place on the island, so there is no soaring around the heights of Gotham itself.” The game was “confined and structured, even claustrophobic.”

Now, soaring around the spires and roofs and power lines of an urban expanse populated by freaks, lunatics, maniacs and, of course, supervillains is exactly what Arkham City is all about. As in a Grand Theft Auto or Assassin’s Creed game there is a strong main story line, but you are free to take off and explore. The game offers dozens of optional side quests, calls to action and chances to foil evil. After more than 25 hours I am still far from finding all Arkham City’s secrets.

You come to inhabit Batman and make him your own because you, the player, are deciding whether stopping the Joker’s master plan is more or less important than, say, stopping a gang fight or a robbery at this exact moment. In the main story Quincy Sharp, the former head man at Arkham Asylum, has become mayor of Gotham and has turned a swath of the city’s slum and industrial zones into a walled superprison where the inmates hold sway. Batman is trying to keep a lid on things as various bad guys, including the Penguin, Two-Face, the Riddler and the Joker, vie for supremacy.

Visually, Arkham City conveys a delightfully dark sense of madcap decay. Basic combat is just that, basic, meaning you can essentially tap the attack and counterattack buttons most of the time against normal thugs. Later you will have to master what can become a daunting array of Batgadgets and special combat moves.