NieR: Automata is an action role-playing game. You play as an android fighting to save the last remnants of humanity from the machines that have overtaken Earth. Featuring multiple playthroughs with different endings, the story plays on expectations and breaks the fourth wall in various ways.
Con Buggy on PC
Some players complain about the game crashing, freezing, their save files mysteriously disappearing, and more. As of June 2018, over a year after the game's initial release, there is still no patch to fix these problems. Not everyone on PC will have these bugs, but it's still quite prevalent. If you continually run into issues, your best bet is to find a mod or play the console versions instead of waiting on an official patch that may never happen.
Con Some boring fetch quests
The pacing gets messed up when you're forced to run certain fetch quests near the start of the game. This is somewhat forgivable after the fun and action-packed introductory level, but the quests themselves are still a drag to play through. Some of the side quests can also boil down to the same thing. Even though these quests give a lot of useful information about the world, they're not all that fulfilling, and you may dread having to repeat them when playing through the game again.
Con Second playthrough can get repetitive
Once you get to Route B, your second playthrough, you may find that too much is the same. There are some big differences, such as the new way you get to see things play out, but a lot of it rehashes Route A, your first playthrough. There's a ton of hacking you have to do as well, which gets pretty boring after repeating it over and over again. But if you stick with it, Route C and onward are absolutely worth the time spent getting to that point.
Con Limited open world
Even though NieR: Automata is technically an open world game, it doesn't always feel like it. It's more that there's a big open space in the center of the ruined city you explore, with branches that lead off to vastly different environments, like a desert, a village, and a few other places. These locations aren't that spacious, either, and it's a bit of a stretch to even imagine all of these places being so close together in the first place. It's not too much of an issue as long as you find the story and combat engaging enough.