What starts out as a fairly traditional fantasy adventure in the first chapter quickly spirals into unbridled creativity in Saving Thanehaven. The protagonist is a knight called Noble, and he and his companion Spite are on a quest to save Princess Lorellina from her uncle, the evil Lord Harrowmage, and if it sounds like you've read this book a hundred times already, that's the point. Before the first chapter is even over, Noble (after getting himself out of a rather nasty jam caused by Spite, his magical shape-shifting weapon which never listens to anything he tells it) is visited by a "virus" called Rufus, who tells Noble that he is a character in a video game called Thanehaven Slayer, and that his actions are (and always have been) controlled by someone called "Mikey" using something called a "computer". He suggests asking the princess if she wants to be saved, which starts a chain reaction that threatens to destroy not only the world of Thanehaven, but every other world in the Land of Computer.
Probably the most unique and positive aspect of this novel is its reimagining of a computer's inner workings as a bureaucratic fantasy run amok. When the protagonists journey to Mikey's phone (it makes sense in context), they travel on electrical currents reimagined in the context of an airport, including going through security before departing and after landing. The "AV", which technologically savvy readers will recognize as the antivirus program, is depicted as a secret police type organization that sweeps in and replaces the "enlightened" characters with identical copies. The CPU is a room full of monitors moderated by a repair man. The "traveling between games" plot feels very much like Wreck-It Ralph, but only lasts for about the first act of the story. After that, the focus switches to the attempt to save the computer from crashing, and gets a little more dry and technical.
Essentially, the novel is asking the reader "How much free will is too much?" The personnel of the computer want total control and Rufus wants total anarchy, and Jinks demonstrates through the interactions of her characters with both each other and the environment that neither of those options are workable, much less ideal. When the novel begins, we see that the characters (unsurprisingly) don't like being forced to do things against their will, and a civil war breaks out when the management, personified here as a blue collar worker called the Colonel/Kernal, tries to restore the game to its original programming. On the other hand, when it's revealed later that Rufus wants nothing less than total anarchy, the reader sees (through Noble's eyes) the entire computer falling into disrepair. Many of it's denizens are killed or maimed, and those that aren't are simply milling around in a useless crowd, not accomplishing anything and just taking up space. Thanehaven prompts the reader to think about how much they can and should contribute to society while still maintaining independence, and the exploration of free will as a "virus" that is detrimental to society will feel like something of a retread for adult readers, but will give the book's target audience something to think about.
The fact that Thanehaven employs familiar character archetypes is both a strength and a weakness. On one hand, it's interesting seeing overused tropes confronted with the fact that they are, in fact, just that, but on the other, most of them are not afforded the chance to really grow as characters. The three central protagonists - Noble, Lorellina, and Yestin - are the most "developed", and I use that term somewhat charitably. Noble has a distinct character arc and is probably the most dynamic character available, but the other two don't expand beyond their archetypes. The supporting cast is composed of stereotypes, and some characters (most notably a unicorn named Lulu that Noble finds in the Recycling Bin who doesn't do or say anything) feel very tacked on and pointless.
Noble begins as a faithful servant of the computer, living out his in-game life because he doesn't know any other way, but once he is exposed to Rufus' way of thinking, it changes him. He becomes self-aware, and unlike the other characters, Noble is not completely consumed by Rufus' anarchistic views. He is the only one who finds the middle ground that allows for some free will within the structure of the computer's operating parameters.
Yestin's main purpose is to spout exposition at both the characters and the audience and he never really outgrows that. Yestin comes from a science fiction game where children are routinely mauled to death by aliens, and Rufus even remarks that the game practically requires the player to sacrifice some of the children. Yestin never seems to worry about this, or anything, throughout the story, and his expositional dialog makes him come across as more than a little creepy, as he is a child who speaks like an adult. He's the only major character with any real knowledge of computers, so he is Jinks' only avenue to convey exposition and technical information to the audience, but it's often done in very shallow ways.
Princess Lorellina seems to have been added as an afterthought by an editor who thought the book needed a stronger female presence. She begins the story as the Action Girl archetype, the "spunky princess", but never really outgrows that archetypal role either. She is not changed like Noble is by the massive existential revelation that she has no free will, but rather reacts to it as a spunky princess would: she haughtily demands that everyone "fix" the problem for her.
All in all, Saving Thanehaven is a net gain. The characterization problems and awkward descriptions don't take away much from the concepts, and it's a pretty solid middle grade fantasy/science fiction adventure that will intrigue it's target audience, though unlike some of the more popular titles like Harry Potter or The Hunger Games, adult audiences will find it somewhat hollow.