(Disclaimer: English is my second language, so I want to apologize in advance for there may be mistakes in the text below. If you find any, please let me know so that I can correct it. I'd really appreciate it. Thanks.)
Review soundtrack: I suggest reading this review while listening to Mirror, Mirror, by Blind Guardian (Spotify, YouTube).
Although it was published barely a month ago, there is no denying that The Mirror Empire, by Kameron Hurley, is one of the most important books of 2014. It has generated lots of (mostly positive) reviews and even more buzz on Twitter, Facebook and other social networks. I was really curious about the novel, because from all the commentary I understood that it was an original and bold approach to epic fantasy. After reading it, I must say that I do not completely agree with that statement.
I do agree with The Mirror Empire being a good epic fantasy novel (gritty fantasy might be an even more accurate descriptor). It has all the tropes that you can expect from the genre: kingdoms in fight, powerful weapons, political intrigue... Even the setting is the classical "return of an ancient magic" crisis. There is, thus, a lot in this novel for the fans of the genre to enjoy.
But Hurley also excels at worldbuilding, with a number of original (and very cool!) elements that make the book stand out. Chief among them is the magical system, based on the moons of the world, that give different powers to those gifted enough to use them. I also enjoyed very much the idea of the sentient plants, the danger they pose and how they influence the way people build and defend their houses, for instance.
The first quarter of the novel, that introduces all these elements, is just excellent. The characters are deep and well-rounded, the plot is dense but intriguing and the pace is almost perfect, with some very good battle scenes in addition to other, more quiet but equally interesting parts. There are so many details (and most of them go unexplained) that you have to read (and, sometimes, reread) carefully to get everything and not miss important clues, but it is totally worth it. Even though it may be an oversimplification, I would say that it has all the complexity of Erikson's Malaz saga (but is a lot less confusing and much more satisfying) with some of Brandon Sanderson's wonderful imagination thrown in for good measure.
If all the book were like that first part, we would have here one of the best fantasy novels of the last few years. Unfortunately, the rest of the story does not live up to the expectations and has many of the problems that I find particularly annoying in modern fantasy epics. The pace begins to drag, for example, and the novelty of the magic system wears thin. But, mainly, the page count feels too high for the story, at least to my taste. You are expected to keep reading with the same attention, page after page, with new names, places, details thrown at you and piling up but with no clear direction in sight. I must confess that I find this exhausting, hard to follow and even boring.
These problems could have been redeemed if The Mirror Empire offered, as many reviews stated, a new perspective in epic fantasy, mainly in what has to do with gender roles. It is true that there are some kinds of characters in this novel, Zezili most notably, that are seldom found in the genre, and also the approach to sexual orientation is completely open and natural, with, for instance, group marriages being the norm in some of the societies depicted in the novel. However, and this may very well be only my fault, that none of that stroke as particularly bold or innovative. I mean, we have already seen all that (and more) in, for instance, Ursula K. Le Guin's work dating 40 or more years back, haven't we? I fail to see how this is relevant when we are more than a decade into the 21st century. But, I repeat it, this may be only my faulty perception and your mileage can, of course, vary.
All in all, I recommend reading The Mirror Empire. It is a good epic fantasy novel and if you are into the genre you will certainly enjoy it. In other case, and if you have no problems with long, complex stories, I believe you will find a lot to like in this book. And if you are like me, not particularly fond of the grimdark and with a tendency to find that books over 400 pages are unnecessarily long, even in that case I might dare to say that you should probably read The Mirror Empire if you want to keep informed about the most important books in fantasy literature. Even if it is not exactly my cup of tea, I quite enjoyed Hurley's novel and I'm sure it will make more than a few award shortlists next year.