I suppose if I had to review TimeQuake as succinctly as possible, it would be to say that if this manuscript showed up unheralded in the mailbox of some editor, there is not much chance that it would get published. There is not much chance it would get read past the first few pages.
This book is a memoir, randomly summing up the life of Kurt Vonnegut and his friends and families, in a series of rambling anecdotes. Mixed in with that is a novel following a science fiction plot about a ten year suspension in free will and its aftermath, the eponymous "timequake". The timequake is never explained in much details, and the characters in the novel are never fully explained, because the action of this novel is broken up by Kurt Vonnegut's memoir. Vonnegut admits as much in his introduction, saying that the original novel "Timequake" was never finished, so he produced this instead.
All of this could be seen as daringly post-modern, and for the most part, Vonnegut's style pulls off the book, at least in the sense that it is readable. But this book could also be seen as a bunch of self-indulgent claptrap, and that is my personal take on it. And I am not antagonist to Vonnegut's works, his idiosyncrasies, or his viewpoints. But his early novels, despite having odd asides and tangential points, did actually have plots and characters, with each sometimes being well developed. "Timequake" is, however, merely a series of disjointed asides and hastily sketched fables.
And the asides, which are often rants, or more formally, "polemics", are also rather uninspiring. I have read Vonnegut's other works, and after Slaughterhouse-5, there is not much more to be said about man's inhumanity to man. And yet, this book's anecdotes are full of repetitious listing of them. Not only that, but there is no real insight or attention paid to why humans act the way they do: the effect is of a smug old man laughing at all the little stupid people.
Being a smug old man with an axe to grind is generally not a desirable thing. Vonnegut's world view is generally humanitarian (and misanthropic at the same time), and he has certainly paid his dues by writing some great novels. Which is why this book has some redeeming features, but for me they can't overcome the basic sketchiness and redundancy of the book.