I finished this book in less than an hour though it is admittedly not for my grade level. But I thought that it was a ton of fun, and I would recommend it for the appropriate age of middle school readers. It reminds me of the old Bailey School kids books, like Vampires Don't Wear Polka Dots and whatnot, and seems to be holding up a consistency of continuity while not getting too bogged down in previous books. Very accessible - somewhat lacking in suspense, but still fun in kind of a goofy way. It doesn't really seem to have much in connection to Lovecraft himself, other than a few shoutouts (people from Miskatonic U. and such), which I appreciate considering how over-the-top racist the guy could be and not in a super subtle way. Though I can't account for the other books I did like the somewhat adult moral choice presented in it which might set it apart from the others - at the very least I wanted to know how they would progress from this point.
Would be a book I'd recommend to people who like Roald Dahl's grossness but with goofy humor.