The most linear and non-interactive game I have ever seen.
The reason why everyone seems so excited about it seems to be because of its emotional story. Well, it may be emotional, but it's surely not a great story. At times very predictable, and also annoying in that you rarely can affect the outcome. You are left as a passive/active observer as some sort who is doomed to witness whatever story the game wants to tell without making much of a difference.
The game elements seems to consist of nothing more than press a few buttons to select from a very limited range of options your character can do. As well as walking around. It's like a super dumbed down adventure game based on the life of a totally normal guy who are experiencing things most people can identify themselves with, such as the horror of losing a son in a tragic "son-teleports-himself-outside-the-mall-so-you-cant-catch-him-in-time-no-matter-what-you-do-to-get-himself-hit-by-a-car" accident..
With the trend being casual gamers who enjoy linear games with lots of graphical awards from very little interaction, I guess the game is hitting spot on for the majority. With it's "sensational" cliche filled emotional story I guess it comes out as something new and fresh. Personally I find it fails as both a movie and a game. For an interactive game it is too passive, and it would never survive on its own as a movie.
So, basically take a boring game, couple with a poor chick-flick and viola, you got a game everyone are excited about.
I recommend to just wait for someone launching a walk through video on YouTube, the game is so linear that it will give you mostly the same gratification. If you need interaction, just press the pause button from time to time, that should simulate the game element pretty well.
In the name of fairness, I will also mention that the game story does branch out somewhat and there are different endings. Also, the graphics is great (for a computer game, poor for a movie).