I finished the game yesterday (first ending) and I was pleasantly surprised by its quality and well executed uniqueness. It took a good eight hours until the game clicked for me, though, and I was almost willing to say people made a lot of fuss about nothing when they were proclaiming how good the story and presentation were supposed to be, but I'm glad I stuck with Nier and eventually 'got it'.
The gameplay itself would never really shine and the subquests were mostly boring and didn't add much, but the mainstory, the amazing soundtrack, interesting bossfights and a localization that is probably as good as it gets (I wish everything was voiced, though) make Nier an exceptional and underappreciated gem. And that is saying something for me, because a good presentation alone is usually not enough for me to stick with a game.
I wish SE handled the marketing for this game better and didn't pretend the game was something else. It almost felt like they were trying to sell this game as the next DMC or Bayonetta when Nier doesn't want and never could compete with these kind of games. Wada aparrently was well aware that Nier would pretty much end up as niche culthit, though, so I'm not even sure what they were trying to do with this game.
Anyway, Nier is awesome, and I can't wait to see what the following playthroughs have to offer.