If this story feels familiar, that's on purpose. In their afterword, author Nagawasabi64 says that they've noticed that the "trapped in a VRMMORPG" genre made popular by SAO has fallen out of favor, which made them want to write one. Since they've always enjoyed the genre, they decided to write The Unimplemented Overlords Have Joined the Party! in an attempt to, as they put it, "throw a little kindling on the dying fire" in hopes that other Narou authors would follow suit. If nothing else, that tells you two things that may contribute to the enjoyment of this book: that Nagawasabi64 is a genuine fan of it and that they're trying their absolute best to write a good story because of it.

Both of those do come across in the novel. Although the premise is perhaps wearily familiar, Nagawasabi64 does play with it enough to make it their own. Taking place inside the in-world VR game Eternity, the plot opens with middle schooler Shuutarou happily creating his character and logging in for the first time. Shuutarou missed out on the closed beta for the prohibitively expensive game but was lucky enough to be one of those chosen to play for free once the game launched. He's delighted, even if the game's proprietary mechanic of giving all players a randomized unique skill gave him the seemingly weird "create dungeon." But he's still willing to test it out and activates it when everything goes sideways: a system announcement from the "Mother AI" that runs the game tells everyone that logging out will no longer be possible. Corollary to that, pain sensors are now permanently on, and death in-game will also mean death outside of it. This will remain the case until Mother AI's conditions for clearing the game are met…and she's not being terribly forthcoming about what those are.

At this point, the narrative splits more or less three ways: Shuutarou and two other players named Misaki and Wataru each get their perspectives. I say "more or less" because Wataru's segments are just as likely to be given to his subordinate Alba, and we get a couple of outlying points of view as well. But the idea of the split remains alive even if it isn't to the letter, and this sets the tone for the story. Each perspective has its distinct plotline, and they eventually come together for the novel's finale before splitting off again, presumably to preserve the narrative structure for the next volume. Wataru and Alba are the leaders of a guild primarily made up of beta testers, and their story is about quelling panic among the players and trying to figure out how to clear the game with as many people as possible surviving. Misaki is a young (middle or high school age) player working towards making the game both survivable and enjoyable for herself, and she ends up helping Wataru when her unique skill is revealed. And Shuutarou? Shuutarou is the wish-fulfillment portion of the story.

His "dungeon create" skill activated when Mother AI was making her demands known, so while he got the message (literally, in his inbox), he missed the excitement of being in his newly created dungeon at the time. But because of the overlap, his "new" dungeon is an area of the game that hadn't been implemented yet, and he finds himself in the castle of the six final boss characters, the eponymous overlords. They don't have any real idea of what's going on, either, and since their quest(s) aren't active, they imprint on Shuutarou as their master, even though he'd rather they be his friends. A short story at the end of the volume about one of them, Vampy, implies that they may not be creations of the game (or at least not entirely), which raises some exciting possibilities for later, and they do all act with much more free will than any of the other NPCs; Misaki's sections do an excellent job of showing us how unusual the overlords are. But Shuutarou knows none of this, and he's just having a blast figuring out how to use his skill to create a monster community within the castle and eventually venturing out to help stop Mother AI's machinations and take out some player killers. He's very much the light in the dark, and the contrast between his story and the others is one of the strongest elements of the novel.

There are, of course, the usual pitfalls. The most egregious one is the usual stat screens. Still, the author can use them fairly sparingly – we only get them as Shuutarou is unwittingly unlocking aspects of his unique skill. Levels are mentioned but not harped on, although there are a few too many reminders of what levels really mean in the game; there's a significant difference between them, and they truly affect what players can do and where they can do it. That repetition is a general issue with the writing, possibly a vestige of its original serialization, but mildly irritating nonetheless. And really, do we need to be told that goblins are foolishly thought of as the weakest monsters in an MMO at this point?

Fortunately, the plot is solid enough to make these feel like minor annoyances rather than dealbreakers. In some ways, the book feels like a (deliberate) combination of SAO, Log Horizon, and Suppose a Kid From the Last Dungeon Boonies Moved to a Starter Town, and that works better than you might expect. The illustrations also help, being very pretty and with a vaguely CLAMP feel in how the artist draws Shuutarou. This may not revive the genre (and we may not want it to), but it's still a fun read that lays out some interesting possibilities for what's in store in later volumes.