I tell people that short story collections aren't novels. This, you might think, is obvious. Yet many people insist upon reading them as if they were novels; start at page one and carry on until page the last. I think this might be why some people end up not liking the short story form: they think the way to read them is 10 - 20 at a time by one author, one shortly after the other. This may not be the best way. I encourage people to think of each story as the basic element, not each volume. Read them in any order you like, read only one then put it back on the shelf, if you want. They are almost always published individually in magazines prior to collection in paperback volumes. Treat them that way and they might appear in a new light.
If my theory were a submarine, this book is the depth charge that sinks it: not only is it necessary to read the stories in order for it all to make sense, it is best read whilst the details of KSR's Mars trilogy are still fresh in the mind (which wasn't the case for me), because we're back on Mars with the First Hundred and others for some stories that didn't quite fit in the novels and they are told in chronological order...except when we aren't, that is. You need to keep your wits about you: some of the stories aren't set on Mars - some are set in an alternative timeline from that set out in the novels. Many assume you know the characters and plot of the novels. Some of the newer characters recurr so that later stories will make much more sense if you've read the earlier ones.
The alternative timeline isn't the only experimental aspect of the collection. Some of the pieces are just documents, e.g. a series of abstracts from scientific papers debating the origin of nanobacteria - native Martian or Earth contaminent? The Martian Constitution in full and a commentary on it. And there's more: a story about KSR finishing writing the Mars novels, a small collection of "poems" - see later.
The quality of the stories varies, some of the experiments are successes, others failures. The best are truely excellent and sometimes shocking. The worst are miserable creatures, not fit for the light of day. I don't like sports stories generally. Baseball stories are the worst of a dire genre. So a "baseball on Mars" story is just awful...the "poems" lack all merit. How many writers have been successful novelists and poets? Scott and Hardy. Can you name another? KSR's verses here don't really seem to demonstrate a grasp of what a poem is, let alone act as exemplars of the form.
But the best stories are great and usually heavily informed by both character and landscape (which will be no surprise to KSR fans). KSR's ability to write about landscape is in fact comparable to Thomas Hardy's. They both make you see it as if you've been there, which makes sense with Hardy's Wessex and KSR's California because they respectively lived in those places. But KSR can make you see the Dry Valleys of Antarctica just as well - OK, he's been there for a few days. But Mars? He makes me see Mars just as well. This is the basis of my theory that KSR is an alien in disguise: he can describe Mars just as well as he can describe the Californian coastline - because he's been there, too!
So that feat never ceases to amaze me and KSR has another talent that is rare - he can write excellently about mountaineering - which is just as well as one of the stories, the longest in fact, is about climbing the solar system's largest mountain, Olympus Mons. The story is thematically like the Mars Trilogy in miniature at least in respect of the whole Red-Green debate. I'm a Red. In fact my Redness is so saturated it is almost black. So I sympathise with that story's main protagonist. (Don't read that story whilst depressed, however - you may not survive to finish it.)
So I rate this volume at three stars - but that is like the mean of the temperature across a year in New York: not much different from that of, say London, but the extremes are much greater. In fact all fans of the Mars Trilogy should read this book remember its triumphs and forget its failures. Kudos to KSR for taking all the risks he did in this book, the ones that pay off are jackpot winners.