It's kind of sad knowing this is the last Michael Crichton book I'll read, because Crichton died in 2008 and this is the second of two books to be released posthumously. This actually is one of his better books, probably because it follows the Jurassic Park formula of opening up a just-credible enough world that has so much going on that it's as much about the exploration as it is about the fights and thrills. There's the wonder of the new world along with the typical techno-driven plot. In this book, the world is the micro scale, what things would look like if you were shrunk to half an inch tall and out in the wild.
I found some of the stock Crichton characters -- especially the annoying academic that he doesn't agree with -- to be especially poorly written. Maybe he writes them badly so you like them even less? But there's some surprises to the usual formula that I liked, although they may have been added by Richard Preston when he completed the novel.
This has all the usual strengths and weaknesses of the typical Crichton novel, and the strength of its premise puts it high on the list, probably of the top 5 Crichton novels of all time. There's one BIG problem with the underlying scientific premise that he never explains (and is particularly annoying to a biochemist), even though a character actually articulates it, so I had hope that it would be revealed at the end, but it's not, and I think ... it's better if you know that going in. Or you can wait for the inevitable movie.
Rest in peace, Michael, and thanks for all the books I read in high school that probably influenced me to become a scientist more than I know.