First off let me say this game is great, and an amazing sequel to AA. Hoping Rocksteady makes a 3rd one, mainly to see what a game after the events of AC's ending will be like.

That being said, I found myself beating the game and all the side missions (with the exception of the Riddler's, which I am still working on) after only 6-8 hours, while playing on hard. I remember AA taking much more time for me to beat all the way, save for the riddles, which took some more time. I don't know if it was because the city felt smaller then AA, or maybe being able to traverse the city faster made it feel smaller, or maybe I just got better at games between the two, but I found myself somewhat shocked when I realized it was all wrapping up.

Anyone else feel this way?

I think it MIGHT just be because you're Jesus, and gangbanged the game, somehow, on your own. I beat AA in about 10 hours on Hard, and 13 for AC. The fact that there was more content and having to wrap around the damn city to get from the Museum to the Steel Mill and back took up quite a bit of time. I've probably spent a good hour and a half of this game in the air, so that might be why it took so long by comparison. I didn't really have any problems getting through any story missions, with the exception of finding the Identity Theft crimescenes, since I did it all in the first day before there were guides and whatnot.

I felt like the length was pretty comparable, and Arkham City offers up more content so I'm pleased with that side of it, myself. Arkham City itself does tend to feel smaller than it actually is thanks to how proficient Batman is at gliding (I definitely wouldn't say it felt smaller than Arkham Asylum, however) - I didn't really find that to be a big problem, though it has left me wanting a full Gotham City to play in in the next title.

I think the game feels shorter cause the inside building locations are smaller. But i definetly spendt more hours on this than i did with arkham asylum.

It felt much longer to me but that was because I spent most of my time leveling, doing side quest, and completing all the Riddler stuff.

story wise it felt it was shorter, but all the side stuff is much more in depth.

yes, it was much shorter. (not including side missions and riddler crap) i beat it within a day (the main story) :(