‘Good Omens’ pokes fun at humanity, heaven, hell, Armageddon.

When two popular authors collaborate on a novel, they create something spectacular. In this case, that honor goes to Sir Terry Pratchett and Neil Gaiman, whose collective work on 1990s “Good Omens” produced a quirky, touching book that remains as engaging today as on its publishing date.
The casts of characters that Pratchett and Gaiman created are the bits of color that readers of both authors have come to expect and love. Aziraphale and Crowley, for example, are a classic odd couple who have, somehow, managed to find a comfort in our imperfect world together as friends, despite being from two places that are quite literally opposite to each other, heaven and hell.
Aziraphale is a fussy, book-loving angel, and Crowley is a smooth, easygoing demon. These are the first characters readers encounter, and it is hard to dislike them in their bickering.

I found the affectations the authors gave the two endearing, and the obvious reluctance with which the two have been performing their jobs is what helps bring on the plot. Essentially, these two are in charge of helping bring about the end of the world, and they are highly disinclined to disrupt their millennia of comfortable existence.
Both Aziraphale and Crowley have been charged to influence the Antichrist, a job that has suddenly become much harder after they realize the child they have been working on for its entire life is the wrong one. Throw in the prophecies of a long-dead witch (as translated and monitored by her descendant), which predict the precise way and place the world will end, and there is suddenly a race on to a very big finish.
After this, the book speeds up delightfully, bringing in witches and witch-finders, schoolyard gangs and biker gangs to face what could very well be the end of existence as we know it.
Pratchett and Gaiman show a marked knowledge and irreverence for Biblical tradition, and the references they make throughout the novel are clever and understandable. It is often hard to see where Gaiman and Pratchett each write individual passages, but at others it is highly noticeable. For avid readers of either novelist, it is almost a treat to see if one can pick out where each author has contributed their own words.
Other characters are just as engaging as Aziraphale and Crowley, even if those two tend to steal the show with their witticisms and sly commentary on each other. Witchfinder Sergent Shadwell and his floor-mate, the clairvoyant Madame Tracy, are almost classical Pratchett characters, down to the mannerisms in their speech.
Readers familiar with Pratchett’s “Discworld” series will be pleasantly reminded of characters from that series, but Shadwell and Tracy are characters in their own right.
Likewise, there is more than a shade of Gaiman in many of the celestial characters, from the Metatron to Beelzebub himself.  It seemed, in a way, that Gaiman had command of heaven and hell, while Pratchett kept himself closer to earth with a host of human characters.
As a lover of the Discworld series, and a reader of Gaiman since “American Gods,” I found “Good Omens” to combine the best aspects of both writers. Skillful editing has made this a smooth, fun read and, clocking in at 288 pages, quite a quick one, too.
It is difficult to find anything wrong with the book, although one might argue that the passages involving a schoolyard gang, simply called “Them,” are sometimes out-of-pace with the rest of the book, which trots along merrily at a pleasant speed, and it doesn’t always grab you with the same strength that other sections do.
Those who enjoy satire will find this book engaging as it takes gentle snaps at humanity itself, although faithful readers of either or both of the authors may find some spark which they’re used to from these stellar writers lacking.
I would recommend readers to not view it as a Pratchett novel or as a Gaiman novel, but as a book of its own, and in that, it delivers.