I enjoy Guillermo Del Toro. I thought the first bits of The Strain were solid, I've enjoyed many of his movies, and so a foray into children's books really seemed like it should have been down my alley. Why, then, didn't this work for me?
The idea behind the story is a kid who is dragged into a multigenerational conflict regarding underground trolls and prophecies and such. The kid is quickly trained to be part of the war and start working to end the conflict.
This book is tough because it can't really decide who its geared toward from an age level standpoint, and can't decide whether it's creepy or campy in the meantime. Del Toro is an expert in both, which might be part of the problem in any regard, but that expectation only further muddies the water. Worse, it's hard to buy the antagonists as a true threat at any real time, which is a pretty big problem considering the impacts we expect them to have and how they're affected others in the story.
It's just a hot mess in a lot of ways. I can see a lot of appeal, and it's not terrible, it's just something I expected a lot more from than what I ended up getting. Kids would benefit from a campy monster book at this age level, or a creepy one, or even one that walks the line in a successful way. Trollhunters, sadly, is none of those things.