Yes, you have to more or less play it a few times, but there are massive variations. It's how it worked in the first Nier, and apparently some of the Drakengard games, though I never played those. And from what little I've heard about this replay value, the chain of playthroughs is significant enough that you might as well not play the game otherwise.

As for the game itself, I just got it a few days ago, about 2 or 3 hours in, and I'm having a blast with it. It's everything I loved about Nier -- the complex story, surreal concepts, deceptively deep characters, gorgeous visuals, etc -- but with Platinum goodness instead of the original's low-budget clunkiness. 2B is a bit flat for a lead protagonist at this point, but given how all of the characters shaped up by the end of Nier, I'm confident that this will soon change.