Mr. Penumbra's 24-Hour Bookstore

Everything felt too brief. While the premise of the plot is interesting and possesses lots of potential, there wasn't enough fleshing out of the storyline nor the characters. The main discovery and resolution happened in the last 10% of the book, which is really short. And at the end of it, rather than feeling like all questions have been answered, I still feel like it's all been a blur and some of that remains.