I would like to break this review down into categories because there are parts that I thought shone and parts that I thought needed a lot more work. I will endeavor to avoid spoilers.
Characters: 3 stars - This is a tough category. I really enjoyed some of the characters, as well as some of the dialogue between characters, but I thought there was some inconsistency in a lot of the characters I liked and I would have preferred to know more about how the main character thought. Her actions seemed erratic and often irrational (which would have been fine if I'd understood her thought process, because people often are erratic and irrational, but since I couldn't get an understanding of why she was acting certain ways I found her behavior jarring).
Plot: 2.5 stars - (4 stars for intrigue/page turning, 1.5 stars for ending and wrap up) Again, I'm torn here in various directions. Parts of the story were very compelling. I read the book in a short period of time and felt pulled along nicely the whole time. I often wondered what happened next and found myself happy to pick the book up and keep going. And, I recognize that the book is part of a series, hence there are things that we will get more explanation for later. However, I felt that many things were still insufficiently explained, or explained in ways that didn't make sense. The ending of the book made the whole first half of the book seem completely unnecessary (I don't want to explain that further because it would include spoilers but essentially, the way the ending was explained made me say, "Well then why didn't they just ___?") So, while I enjoyed the intrigue of the plot as it was carrying the book along, I didn't think the explanation at the end was worthy of the rest of the book.
World building: 3 - Bonus points for a fairly creative world, but serious points off for not taking full advantage of the world created. Don't get me wrong, I appreciate that there weren't any giant info dumps explaining the minute details of how the world works, but I felt a large disparity between what we were told about the Land of the Sun and what we saw there. For example, we're told it's a place with a lot of magic and thus the people of the land of the sun look down on the people of the land of the stone, but then... aside from some creatures that are used to light rooms, the occasional centaur, and the very specific magic relating to the willows and the protagonist, we don't actually see any of that magic. I would have enjoyed learning more about how the land of the sun worked and seen more of that magic.
Writing: 4 stars - stylistically, I enjoyed Linton's writing. I realize that's subjective, but I liked most of her idea of how dialogue and description should flow. Again, the plot drew me along nicely. What's impressive is that it did so despite a number of editing flaws. I think that I would truly enjoy reading more works from Linton with more thorough editing.
Editing: 2.5 stars - So, the editing flaws mentioned above... I was thrown out of the story repeatedly (though not so much as to make me give up) by typos, word misplacements, inconsistencies in time, and the occasional incorrect tense. I also think an editor could have helped with some of the overlying plot and character issues.
All in all, I enjoyed the story and will in all likelihood buy the second book when it comes out. If the sequel is just as well written, but even better edited, I will probably call myself a fan of Ms. Linton.