At first I thought this was going to be really good. We start with the sad, pale war orphans roaming like animals or ghosts through the vast manor house and eavesdropping on servants. Then the as-yet-unexplained "Grisha" show up with their mysterious tests and unknown powers. Then we jump forward a decade and see our orphans grown up, or nearly, and enlisted, marching through a cold, grim land that seems perpetually at war. They must brave the almost-impossible crossing of the Unsea, a region of darkness created by catastrophic evil magic and peopled by man-eating flying monsters.
When our pleasingly plain and charmless heroine manifests unsuspected (by the characters) Specialness, her world is turned upside down and she is whisked across the kingdom to the capitol, where she will be safe from assassins and learn to use her new power to Save the Kingdom. The description of the palace-within-a-palace and its ornately carved walls and over-the-top luxuries was well done.
And then Alina becomes a student Grisha and the whole thing collapses into YA generic-ness. All the other girls are gossipy, bitchy Mean Girls who are Mean to Alina. I suppose this is intended to make Alina likable by comparison, since she is otherwise a whiny, self-absorbed wet blanket. She crushes on two boys and feels inferior a lot. There are dresses and make-over scenes. Alina becomes magically pretty.
Without giving away any plot twists, I will say that the book got better again in the last section, although not as good as I was hoping at the beginning. But overall, the main thing that makes this book stand out from the YA fantasy-romance herd is the vaguely Russian setting. The characters and magical system were minimally interesting.