I am an unabashed fan of Rick Riordan. Not every book is great, but most of them are quite fun and worth reading. The Hidden Oracle is the start of a new series in the same world and time as Percy Jackson. (Percy is in the the book briefly). Riordan is continuing to build on the story from other books. So there are references to other books and story lines that you will either need to remember or just accept without knowing.
Apollo is a self-centered narcissist. Everything is really primarily about him. And this is told in his voice, so especially the early book shows a former god that can’t understand why everyone isn’t doing more to help him. The reader understands that he is annoying. And readers of Riordan’s earlier books remember why Zeus was mad at Apollo in the first place and why the other characters are not particularly fond of him.
The storyline is pretty standard. There is a problem, a quest and a cliffhanger for the future books. There is character growth and development and a little bit more insight into the unanswered questions of previous books.
I enjoy these books, not because they are completely original but because they are fun. Teens with significant power, and responsibility, are exactly what I wanted to read about when I was an early teen. It has been a few years since I have read significant amount of young adult literature, but I do tend to keep up with Riordan.
As a general ranking, I think this probably isn’t quite as good as the original Percy Jackson series. I think it is better than the Heroes of Olympus series. And I think I need to read more to decide whether I like it more than the Gods of Asgard series.
(This is lendable on kindle, like most of Riordan’s books. Let me know if you want to borrow it.)