Mostly great
But the story was much much stronger before the reveal at the end. I don't want to say too much here in case people who haven't played read the reviews but I felt so much more involved when the story was just about normal human drama. I thought the gameplay was a really great analogy for a normal man's problems, relationships and regrets. I think it's a shame that you felt that wasn't enough to base a game around. It's this sort of simple stuff that's really missing from games in general and whenever I stumble upon some it makes me realise how potentially powerful games can be. There wasn't anything really wrong with pulling a twist like that, I just think it cheapened the very genuine stuff that came before it.
Anyway, I really don't want to give the impression I didn't enjoy this because I really did. The idea was great, the story was great when it wasn't being too melodramatic and the music set the perfect mood. Working a slightly different gameplay style into the flashback scenes was a brilliant idea. They were probably the strongest part of the whole game and your cut back to reality was more heartbreaking than any cutscene could have been.
Overall an excellent game. Just next time you make something so emotional, please consider keeping it more grounded. I know it's difficult to write restrained stuff but you don't always have to go to extremes to find great drama. If your ending had been as subtly handled as the rest of it this would have been a masterpiece.