I finally got around to playing Arkham City, and it's taken up a fair chunk of my free time over the last week. I think I'm close to finishing the main story, but there's so much other stuff to do that I keep getting distracted from it!
Man... The Riddler trophies - there are SO many of them. I especially despised having to get Catwoman's trophies, since it's much slower getting around Arkham with her.
Some of the riddles are pretty obscure as well, even after getting marked to your map, it's still painstakingly difficult to find the exact position in which you have to be, or even the location of the riddle.
The story is great, but I would have preferred it longer, along with the addition of more characters from the Batman franchise, along with being able to play as Robin and Nightwing in the main story, in the same way you play as Catwoman during the main story.