I can see why people loved this.
I'm torn between giving it 3 stars and 4, because while it wasn't what I want in a fantasy story, it is well-constructed for the type of story it is. Sadly, it's just not the type of story I like.

So what is it? It's a romp. A group of D&D archetypes in a world where D&D adventurers are treated like rock stars, quite literally. They're not just treated well: the story is framed as if they were a modern band in a medieval world, dealing with things a modern music act deals with. It is not a comedy, however, just a lighthearted adventure story.

It's packed with references to bands and music, which is not an area of trivia I'm great at, but I could identify things as references even where I wasn't sure what they were references to. Despite that, the plot bumps along at a decent pace, and the interactions are fun. The characters aren't particularly deep, but they're interesting and believably drawn for D&D adventurer archetypes.

If those elements alone seem good to you, then you'll have fun with this book and you should give it a read... but you should expect that there aren't really any other elements to the story.

As great as Eames's work is at the things it does, the grim specter of Chekov's Gun looms over the entirety of it. Not even the slightest thing is introduced unless it is part the plot; that's often hailed as a positive in a dramatic criticism, but in fantasy literature it saps the vitality of the world and leaves the background feeling two-dimensional, like the flat backdrop of a play that is wheeled in and out as the actors strut upon the stage.

The mysterious depths of Tolkien's mythos, the sprawling madness of Mieville's Crobuzon, the perplexing intricacies of Bancroft's Tower... those just aren't here. None of Eames's book concerns the ordinary citizens of his world, and so we learn nothing about their lives. There is no hint of history or mythology to the world which does not directly impact the lives of the characters. Even their own past lives are largely in service to the plot. Absolutely nothing extends the world beyond the pages.

For me, the essence of what I enjoy in fantasy is that sort of magical tourism. I love to wander the shire and imagine the smell of flowers baking bread, and to know that Sauron was apparently a problem for some ancient kingdom that never comes up again in the story. All those details and depth create an experience beyond a simple recounting of the plot, and Kings of the Wyld is missing those things. There's an ancient empire, but they go there, there's some gods, but they meet them, there's some grand mythic underpinning to the world, but only because their story traces to its origin. Nothing ventures beyond that. There's no menace of Jabba the Hutt and his gangsters hanging off in the corners; if it's mentioned, it shows up and is dealt with.
Everything is Chekhov's Gun.

It is, in essence, a pastiche of a random D&D campaign, run by a DM who loves music and doesn't have any particular setting information in mind. It excels at recreating that experience... but it doesn't do anything more than that. It's fun, but it's a bit shallow. If that's the kind of book you can enjoy, then you will love this. If you expect more, then it may be mildly disappointing, but otherwise unobjectionable.