It is AWESOME, I ended up playing for like 13 hours without even realizing it. I started sometime yesterday afternoon and finally went to bed at 5am, it was ridiculous. There are CSI type scenes where you get to reverse and fast forward a scene to figure out what happened. There is a twist in the game as well. Going to start again today. Good thing it's shitty and cold outside, makes for good video game weekends.
I have the collector's edition, it's absolutely insane what you get with it. There's a tooth and casino chip in evidence bags, a package with a Batman wanted poster and a bunch of police files on characters, a Wayne family picture, an Anarchy logo stencil, a book, a glow in the dark map of Gotham City, batwing prototype blueprint, and an awesome Joker statue with an LED background and a hidden item in a small bag that has a spoiler warning to not open it until you finish the game. The Joker statue is amazing.