Wide-spanning and imaginative. If you're feeling sceptic in the beginning, give it until at least the second set of characters are introduced proper—I feel that's when the book was coming into its stride.
Consistently entertaining and engaging, I never felt like I was slogging through a chapter to reach the end. At times, a bit too many pop-cultural references, but within acceptable bounds given the YA bent of the novel.
I'd say this is recommended if you're a fan of other Tchaikovsky novels :)