Awkward walking through a great story
I think that in a certain sense, reading up on the well publicized idea that there are no "game overs" actually enhanced my enjoyment of this game. Knowing that there were no restarts or endless retries definitely ratcheted up the intensity, especially in a game where the subject is a murder mystery. Also, the expectation laden in most video games that "if you fail, the story starts over" actually made that knowledge required for me to enjoy the game at all. The story progressed so smoothly from one scene to the next, that if I didn't actually know that my decisions made an impact (see all the possible endings), I would have declared this to not even be a video game, but an animated movie.
Graphically speaking, Heavy Rain alternates between impressively detailed to "buried so far into the uncanny valley, archaeologists will find it in a thousand years." That's one of the two factors that will occasionally take you out of the experience. The other factor are the walking controls. I actually like all of the context sensitive stuff which is well executed, but the walking around itself it so freaking awkward and outdated. There frankly is no reason why the walking is as bad as it is.
But realistically, we're here for the story. It is deliberately paced at first, almost painfully so. But once things pick up, it starts to get crazy. There were a few points in the story where I thought to myself, "I've already solved the mystery and I've played this game for only 2 hours. They are telegraphing this one so bad." But by the time I got to the end, I can safely say that I didn't see the ending coming.
I definitely need to be in a certain mood to play this game. There aren't a lot of games with similar experiences out there currently. It's not perfect, but it is one of the more unique experiences I've had in gaming.