Heavy Rain by Quantic Dream is not your typical game; there are no powerups, no extra lives, no high score. Nothing there to reassure you that you're doing something good, nothing there to stop you when you're doing something bad. You don't play Heavy Rain - Heavy Rain plays you. The sooner you realize this, the better you will savor this experience.
I'm sure you've already read reviews describing the storyline and the game, so I'll just tell you this - be prepared for a wild ride. Never in my life have I ever gripped the PS3 controller tighter than when I played Heavy Rain scene after scene.
Know how tense you get when you really get into the action sequences or dramatic moments in movies, sitting at the edge of your seat, clenching your fists and grinding your teeth until the moment's past? You're gonna get that sensation with a thriller like Heavy Rain - except you're smack in the middle of it, and the story won't stop.
Don't get the gameplay mixed with the QTE (quick-time events) of other games - Heavy Rain won't, for the most part, wait for you to enter the right input. All your actions bear consequences, whether immediate or not. And while the beginning of the game puts you in training wheels to get the hang of things, later events will require fast reflexes and quick thinking that won't stop until the scene is done.
The graphics and voice acting themselves serve adequately as a good delivery mechanism for the thriller's gritty atmosphere. The gray undertones are enough to convert the happiest man into a full-fledged emo, and the facial features are convincing enough to invest all your emotions into each scene. The voice acting, at times, can feel a bit off and out of place, but overall sets the mood just right - whether someone's angry at someone, or another person is tearfully crying about a memory.
Even though you're (for the most part) in complete control of your actions and choices, Heavy Rain doesn't give you all the time in the world to make them count. The events that occur in the game are happening on their own timeline, and you really don't have time to play the "what if" game to see all your options. This becomes very real in certain scenes when the dramatic tension demands all your focus on what's happening right before your eyes.
Sure, there is a pause button, and sure, you can replay certain scenes again and satisfy all your "what ifs." But doing so will break up the continuity of your current storyline, and who wants to ruin an already-playing movie anyways?
Besides, you're likely to blow through the game quickly once over, take a break, and start it all over again, just to see what other choices you can make that can alter the story.
Heavy Rain is probably the start of interactive games/movies done right, giving you multiple movies in one package and sitting you in the director's chair controlling all the action. Whatever fate you decide for the 4 playable characters in the game is up to you, and the story that you will create is yours alone to enjoy. In my book, that is the ultimate game customization.