The Dark Knight, the characters all look great. I especially love Scarecrow's look in the game. The voice acting was also terrific. Rocksteady brought in Mark Hammil and Kevin Conroy who were the voices of The Joker and Batman in Batman:The Animated Series. Everything fit together very nicely.
I usually find myself struggling with combat games that focus on combo moves, but once you understand the flow of the combat system you can start to pull off some crazy attacks and they look so cool it feels very rewarding. Of course, you can avoid combat with some trickery and stealth as well. Don't want to fight right now? Why not lay some explosive gel as a land mine or throw a Sonic Batarang in a corner to lure some unsuspecting thug into an ambush? Batman:AA leaves a lot of the fighting up to you which has the fantastic side affect of making it so when you are required to fight it doesn't feel so tedious.
The entire time I played Batman I felt like I was playing a cross breed of Assassin's Creed and Metroid. I was leaping from guard towers, gliding, grappling, rolling, zip-lining, and running all over while constantly backtracking with new gadgets to find new secret pickups or solve riddles left by The Riddler. While this backtracking does not net you upgrades directly, every riddle, trophy, etc. you solve/find grants you experience points towards your next level. In my first play through I collected all of them because it was truly enjoyable to search the depths of the asylum and solve riddles. Now I'm playing Hard mode and backtracking is practically necessary as the quicker you get upgrades the less likely you are to get your teeth kicked in.
I'll touch on Hard mode quickly. It's actually an interesting way to play the game. Timers for time bombs disappear, you aren't visually notified of incoming attacks to know to hit Y (Counter), thugs can obliterate you... The game just hits a new level that rally pushes your skill. Somehow it's a lot of fun as a second play mode. I do not recommend it as your first game file.
I think the best thing I can say is that I am playing it a second time. I'm also enjoying the Challenge Rooms. I'm usually not drawn to these types of mechanics, but I find the Silent Predator rooms to be great fun. I don't think laying out my careful plans setting traps, watching thugs drop one-by-one, or watching their buddies begin to panic will ever get old. Even the combat rooms are growing on me as I get better at the combat as I play Hard mode.
Some of the boss fights seemed less than creative, but I ignored that since I couldn't think of a better idea for them myself besides just not having them as a battle (one in particular that I won't say to avoid spoiling anything). Sometimes the game can also feel cheap when you get hit by a brick thrown by a thug you didn't even see off screen destroying your x37 combo or when you're certain you hit Y but Batman didn't counter. The problem I had most often was Batman attacking in a different direction then I told him to after coming off of a finishing move. He'd attack thin air most of the time and ruin my combo. However, I can't be sure these events weren't my fault and off screen enemies is just part of the larger scale fights.
Batman:Arkham Asylum has set a new bar for my expectations from now on and I hope Rocksteady and other studios can put out this type of game more often.