Game was fun once all the guards started coming after you. The problem is I didn't really understand what was going on, and what exactly was happening. Wish the game would have had some kind of tutorial to let you know what to do and what certain things did. You pretty much hit the ground running and have at it. Having said that game was fun, and will try it more in depth at a later date. If you like first person shooters give this one a try.
As most people say, this game is absolutely beautiful and well crafted. The characters are interesting and well executed & the plot is engaging. It's a wonderful game and definitely polished. I'm glad they created a new sky environment (rather than revisiting Rapture for a 3rd time). The floating city was an great setting for a game.
I read a few reviews where people said it had a "bad ending"... and I have to say you likely didn't understand it. I didn't understand the ending either and went back to read an explanation. After reading what the ending meant, it all made sense and was awesome and more interesting. In a generation where stories are mostly paper-thin, this game exceeds in storytelling by leaps and bounds.
As far as the gameplay, it's pretty standard Bioshock with a few minor changes. The rail system mechanic was new and gave a different change of pace to the action. The guns are pretty standard, nothing really new there. The plasmids are also pretty standard Bioshock (I used them all about equally, except for "Return to Sender" which I found useless).
I gave it 9/10 because the game is well crafted and deserves a high score. I didn't give it a 10 because the guns/powers were all standard FPS we've seen before.
Don't believe the hype, just rent it for yourself and see what you think. I wouldn't buy because I don't see much replay value.
There is one thing I can point out about this game that is wrong. The story tries to make you sympathize about what Booker and Elizabeth have been through but forces you to shoot people in the face with firearms and magic. The story by itself is amazing at every twist. The gameplay is spot on. The colors are amazingly vivid. I wish real life looked as good as Bioshock. Even the soundtrack is amazing. I mean, come on. It is astonishing how good this game is.