Just shy of four stars for the rushed ending (I guess it sets up the next books nicely, but still). 

I don't see a lot of fantasy based on Russian/Slavic myth; it's refreshing to see my culture portrayed in this way, without over-explaining itself on every page. Even the sentence structure when characters speak is evocative of the Russian language. 

Still, a little to YA-ish, or tropey, for my taste. I also feel that the McGuffin wasn't set up well, and didn't pay off -

the talisman seems to have been given to Vasya by Morozko, but Morozko acts surprised she has it and it doesn't really factor into the final battle?

The writing is evocative and beautiful, however, and the overarching theme of the conflict between old gods and new was presented well.