This is the story of how Victor Frankenstein got interested in the off-beat pseudo-science that would lead him to create his famous monster in Mary Wollstonecraft Shelley's Frankenstein. I've read the original twice and am just not a huge fan -- I don't like any of the characters much, and that's such a deal-breaker for me. But I thought this looked good, and I have to admit that the cover art intrigued me, with its almost western feel, so I read it.
I don't like it any better than Shelley's book. Victor Frankenstein was arrogant and impetuous, his twin brother Konrad was too perfect to be terribly likeable, and their mutual love interest Elizabeth was too wishy-washy with her affections. However, I also felt compelled to finish reading it and find out what happened -- it's very well-written and has an intriguing story: Victor turns to alchemy in a desperate attempt to save his ill brother. It's got lots of exciting adventures, a love triangle (because we just don't have enough of those), and a treasure-trove of historical details.
So if you like YA fiction, historical fiction, or books that expand a classic story, you might dig this. My reasons for not liking it much are totally personal and not a reflection on the writing.
If this was a movie, I would rate it: PG-13 for danger and suspense and some creepy imagery.