It takes ~30ish hours to get endings A,B,C,D,E; realistically they're 3 story chapters, with the 3rd chapter having 3 different endings. For a typical JRPG that isn't anything out of the norm, I would say the story gets interesting halfway through the first chapter and gets continually better in the 2nd/3rd chapters.
The main theme of the game is one only a game could have and it's nothing boring like "robots have feelings".
>Robots have feelings and souls? Nothing is what it seems? Humans are the bad guys? With a few twists telegraphed two hours before they happen?
These aren't even the twists in Nier Automata, these are surface-level readings of the story from the first few hours of the game. Although, humans are the bad guys isn't even in the game at all, the humans are long dead. Which I thought was one of the more obvious story twists.