A game in its own genre, with a great story that will have you guessing til the end. Prepare to hold your breath.
This experience is a truly well-crafted masterpiece of innovation and story telling. Try the demo and if you like it, buy the game. The replay value is there for two reasons: playing again to see what happens if you do things differently, and playing so that other people can watch it like a movie.
I had a friend over when I started the game and he sat and watched all the way through. He denied the offer of the controller, unable to accept responsibility of the characters. He just wanted to watch and as I cringed choosing the press of a button, he shouted out at the results... repeatedly. Never have I experienced a game or entertainment experience like this. You owe it to yourself to at least take a peek.