So, as the story goes, Arkham City takes place 12 months or so after the first game, Arkham Asylum. Somehow Quincy Sharp, the former warden of Arkham Asylum has successfully managed to run for mayor, and convinced all of Gotham that it would be a great idea to wall off a chunk of the city and turn that chunk into a big-ass prison. Sounds logical? Not especially, and the start of the game does a very poor job at explaining what exactly has happened between the two games. I hear that there's some sort of comic out there that shines some light in to this, but fuck this cross-media bullshit.
With the back story (or lack of it) out of the way, lets look at the gameplay. If you played Arkham Asylum, you'll know exactly what awaits you in Arkham City. Arkham City, like Arkham Asylum, does a fucking excellent job at making you feel like a total fucking bad-ass, crushing fools left and right, while remaining very simple to grasp and still offering more depth if one chooses to dig deeper. The core remains the same, punch and counter, stun some special guys and leap over other special guys. On easier difficulties you can pretty much button mash your way through most of the encounters, but the harder the difficulty, the more important your tactics, reading enemy movements and timing your punches will be. Quickfire gadgets and additional special combo moves can help you in crowd management and knock down bunch of guys at once, making those big crowd encounters easier.
The other side of the combat coin is the predator stuff, which is also very familiar, with some welcome additions. You will still grapple between vantage points that may or may not be gargoyles, do inverse takedowns, sneak around silently, watch the heartbeat of the thugs skyrocket as you reduce their ranks one by one. And of course scare the shit out of the last thug. It's still a lot of fun. Your predator arsenal isn't significantly different from Asylum, the thugs however have a few new tricks up their sleeves that make these sections more challenging especially towards the end of the game. The most important is probably the signal jammer, which interferes with the detective vision.
Both the combat and predator challenge rooms also make a comeback, and are exactly what they sound like. A walled off location from the main game and you either beat up dudes for big combos and scores, or race against time in the predator leaderboards.
Biggest addition to the game as a whole is the big city, but anyone expecting this to be a big open world game… it's not. That's not to say that the city isn't fun to screw around in. They made the divebomb traversal fairly fun (though nothing can beat Super Mario World divebombing), but when you get the grapnel boost upgrade, the traversal becomes a breeze. A downside to this large city is that they didn't fill it with enough interesting things to do. There are a few side missions that you can do, but in reality the city acts more like a hub. In Arkham Asylum the island was the hub, now the hub is just bigger. Most of the time you'll still be inside a building of sorts, just like you were inside buildings in Arkham Asylum. There are a tons of Riddler trophies to collect in the city though, if you are into that sort of thing. Dropping in on unsuspecting thugs every once in a while is fun for a moment, but sooner or later you'll reach a point where you'll just want to haul ass from point A to point B to move the story forward.
Another somewhat meaningful addition is of course the second playable character in the story. The four Catwoman sections take place here and there during the main story thread, but aren't so significant that you wouldn't be able to enjoy the game without them, as they are placed behind an online pass style paywall. New games include the code for the Catwoman DLC, but you can buy it separately for $10 if you get your game used. Catwoman plays more or less like Batman during combat and predator sections, she has a few less special moves and gadgets than Batman, but is faster in her main moves. She's also silent and can run behind thugs without making a sound, which you pretty much have to do all the time if you want to have any chance at the predator challenge room leaderboards.
Arkham Asylum was a gorgeous looking and sounding game. Same is true for Arkham City. The music is just the right amount of brooding, visuals are top notch on all platforms. Sound design is excellent, never has punching dudes in the face sounded this good. And the voice casting and acting, fantastic. The entirety of the cast is excellent, but Kevin Conroy's Batman and Mark Hamill's Joker are of course the only true voices for these two characters. But I also have to mention Nolan North's Penguin, it's not your usual Drake-esque North. That man has more range than most people give him credit for.
As I mentioned earlier, the game doesn't do a great job at telling you what is going on in Gotham. As you go through the game, it sheds a little light on the backstory, but some of that stuff is locked behind Riddler challenges and such. So depending on how you play your games, by the end of this one you might still have only a very vague understanding of how exactly this prison came to be. The story told during the game however doesn't have problems like that. It does a great job at sectioning itself in a way that the main story thread is always moving in the background with some subplots occasionally taking the main stage to introduce some other villains aside from Joker and Strange.
It's very easy to compare Arkham City to Arkham Asylum and see where they changed the game for the better. But it's also very easy to see how similar City is to Asylum. One of the strongest aspects of Asylum was the pacing. City loses some of that with its bigger environment. It's also very easy to nitpick on some minors things, like that you still need to mash a button to remove vent covers. It was such a useless mechanic in Asylum, and it's still useless in City. It would be very easy to give it a relatively bad score because of how little has changed, if that's the kind of person you are. I'm not, and the 2 years since the first game's release is more than enough time for me to want more Batman adventures of this kind.