That question alone is what got me interested in the game. I am not a huge fan of how the industry is moving toward beautifully grotesque first person shooters that show how awesome it is to fill a guy with bullets. The intimate moments between a father and son on the other hand is what I like in my movies, and up until Heavy Rain, I have never seen it done (or make that, done well) in a video game.
The ability to show these moments of reality--i.e trying to find your son in the mall through a crowd of people--can only be done through the games unique way of controlling the character. Similar to Quantic Dream's previous game Indigo Prophecy, Heavy Rain doesn't let you just run around like a chicken with your head cut off (although that's probably the feeling that Ethan gets when he loses his son), instead you'll have to move the controller left and right to push through the crowd. Or in the game's more intense moment, when you have to fight another character, you do not enter a fighting engine similar to Tekken or Street Fighter. Rather, the screen gives you buttons to press or directions to move the controller in order to hit, dodge, or (if you wait too long) fail in order to progress the fight along.
And if you happen to fail all of the button presses and your character dies, the game does NOT end. That in itself was revolutionary to me. You control four characters who are getting themselves into some deep trouble with the law or other criminals and if you fail to complete the task in front of you and your character dies the game moves on to the next character. Now, don't go thinking that there death means nothing to the overall progress because it definitely does. If a character dies, then all of the information about the killer that you might have gotten will be lost. Moreover, the interactions between that character and another main character will be gone ultimately changing the entire flow of your story.
And these ability to choose who lives and who dies or what tasks to do and which ones not to do all lead up to how the game ends. Although I've only beaten the game one time through, the game definitely hints to you that there are other ways for the story to end (and you get different trophies depending on how it ends too for you trophy fiends).
I've talked about all of the cool mechanics of the game, but I have to also say that this game isn't for everyone. It starts out incredibly slow to set up mood and character tension. I personally loved it, but if you like games that want you to run and gun in the first five minutes of play, this is NOT for you. It takes patience, but the end result is fantastic.
In terms of graphics, Heavy Rain is really uneven. At times, the game looks amazing. The water effects are great. The characters move like real human beings, and the attention to the tiniest details are great. Other times, however, there are obvious clipping issues that make you wonder how something so simple could have gone unnoticed. Also, some background characters look bland and boring, and this wouldn't really matter in most games, but considering that Heavy Rain is about creating an entire world, it is noticeable when you see the same ten faces in a crowd in a train station.
Heavy Rain is a grown up, high tech version of a choose your own adventure story. Like those books from my past, Heavy Rain gives the player the freedom to play how he or she wants, which is the true role playing game. I'm not entirely sure what Heavy Rain will do to the future of gaming, but without a doubt, Heavy Rain has challenged the conventions of how a game should be played and that alone makes this game a must play. If they had also challenged the way a game should look (like Uncharted 2), then this game would have been perfect. As it stands, Heavy Rain is made for the true RPGer. It doesn't have random battles or crazy weapons, but it has a story that will pull you in and characters that you end up actually caring about. Heavy Rain is a true contender for GOTY.