Imagine Crow T. Robot and Tom Servo roaming the galaxy at will, enacting vast Platonic thought experiments while exercising nearly godlike creative powers. Toss in a whole lot of whimsy and wordplay and just a dash of dizzying scientific speculation and you might have some idea of what Trurl and Klapaucius, the weird heroes of Stanislaw Lem's Cyberiad are like.
The book is utterly charming.
There is not an overarching narrative per se; rather a series of "sallies" in which the duo enact different fictional tropes and plots, some of them bewilderingly recursive. The irresistible allure of certain fantasy princesses is a common element -- Lem's version of our mechanical descendants do have sex lives -- as is speculating about whether those mushy, gushy, sloppy, gloppy organic things they call "palefaces" created the glorious robot race, the inheritors of the universe, or vice-versa.
It's a lot of great, head-scratchy fun. I would particularly recommend it to fans of Walter Moers' Zamoria books, which Lem surely must have inspired and influenced (and if you haven't read any of those yet, I envy you the treat of experiencing them -- and this -- for the first time. Books like these are why it's fun to be smart!)