This short book, largely in the form of Socratic dialagues, is jam-packed with powerful satire. Set in the distant future, it reminds us that every age, indeed every generation, has always been convinced it was something special, that it alone had finally sussed out the universe (more or less), and that their ancestors must've been feeble-minded half-wits not to have seen what is so obvious to them.
I found it an excellent antidote to the implicit universal view that we've just reached the zenith of significance and sophistication, just because we happen to be alive in this era. (This view is like the Anthropic Principle applied to history; the book punctures it sweetly and efficiently.)
The laughs point both ways - how wrong the "past" (present) age was about the world, but also how wrong the "present" (future) age is about its understanding of the "past" (present) age. The interpretations from the future of the few surviving fragments of the present age in the far future are slyly hilarious, while the "our ancestors must've been chuckleheads to believe THAT" philosophy (that we would apply to the ancients' geocentric astronomy, for instance) is applied with great effect to some of the foundations of our current world-view.
There are echoes of Ackroyd's theories about personality of place as expressed in his London: A Biography, Plato's philosphy and Socrates' life, and a poetry of perspective.
The identity and future interpretation of the handful of cultural artifacts from our era that survive is one of the incidental joys of this work, I'll just hint at one of the early ones: that classic comedy, The Origin of Species, by Charles Dickens...