Batman: Arkham City is the follow up to the successful Batman: Arkham Asylum from rocksteady studios. The first game took everything about comic book based games and turned them on their head, completely re-writing the public's view of what a great franchise based game is.
While the first game was fairly linear, which is by no means a bad thing, the second game instead opens the game up into an open world, allowing awesome free roaming and tons of collectible riddler trophies to be scattered around the environment.
As far as how Bruce Wayne gets placed into Arkham City, and how Arkham City was constructed it is fairly far-fetched and definitely falls within the realms of comic book story telling as apposed to following the plausibility and reality of the recent Nolan films. That being said, once you get past the ridiculous set up for the story, you are really immersed into the world, wanting to stay up just a bit longer to get that last collectible.
The only thing I didn't really care for in the story of the game would have to be that it most definitely suffers from villain fatigue. While there were hints to villains that were not part of the story in the first game, this game blows the lid off of keeping secrets, save for the Scarecrow who did appear in Arkham Asylum, and lets you maim and beat nearly every main stay Batman villain. This does lead to quite the surprising ending, but it isn't so far reaching that it is implausible, especially in the context of the convoluted storyline. It comes off as annoying, even though it is cool to see all of the Batman villains.
Then you get the challenge mode, which strips away the open world and gives you closed environments with set objectives, really evaluating the way you handle your skills learned from the campaign mode. I found myself using gadgets, which I didn't really use much in combat unless I needed to, just to help push my score above the high requirements to obtain the highest rankings.
The game is extremely well paced and never feels like there is too much going on at once, but the story isn't as focused as it was in Arkham Asylum. The combat mechanics are the same, as is the set up of 'casing' a room and luring and baiting baddies around the room without being seen, and that is still fun. This game is a superb buy for anyone looking for a good romp as the caped crusader.