I beat Nier: Automata last week and I'm still exhilarated by the ending. What they did at the very end was nothing short of brilliant. A beautiful use of video game mechanics and conventions.
Overall, Nier: Automata was an excellent game. It played well and had an interesting story line. Combat was fun and fluid. The sequence before the final fight was beautiful. I liked a lot of the mechanics like skill chips and the auto-use chips. The game did quite well at reinforcing the idea that the main character was an android through game mechanics.
I strongly recommend Nier: Automata to everyone. One thing to note is that game says it has multiple endings, unlocked through multiple playthroughs. That isn't quite right, and it is a little confusing at first, but it's hard to explain without significant spoilers. Just keep playing, and you'll know when you've reached the true end.
Some thoughts on the "true end' are below the break. Lots of spoilers.
I loved, loved the sequence they pulled off during the very end credits. Presenting you with a hopeless fight, having other players encourage and then help you, and then offering you a chance to help others at the cost of your saved games was brilliant.
So much of modern gaming is aimed at keeping you playing. Have you done all the side-quests? Have you got all the achievements? Have you collected all the things you can collect? Have you reached the maximum possible level? Have you played through all the DLC?
Nier: Automata was willing to say that it's okay to stop. That you've done enough. And they reinforce that by actually convincing you to delete all your saves! All to fuel a mechanic that game tells you will get no recognition, no feedback.
That was outstanding, and fit perfectly with the story they were trying to tell.