A game-changer, not just for Batman but... games. The dynamic camera that shifts from a Resident Evil 4 esque over-the-shoulder immersion to wider views for combat is at its most polished at this point; the combat itself - chaining hits and dodging attacks in single sweeping moves - has never felt more satisfying. For the fans of the Caped Crusader, there's also an abundance of gadgets, villains and subtle references to previous media. It also retains a dramatic self seriousness that works mostly due to the fully realised Gothic visual style, evocative of the graphic novels and even the Tim Burton movies.
The sequel, Arkham City, is a degree fattier than this one but is a vast broadening of the area you can explore for side quests, Riddler collectables and other various goodies.