So Cixin Liu’s The Dark Forest and Death’s End complete the trilogy started in The Three-Body Problem, and this is definitely a case where reading the whole series changes my opinion of the first book.
Because the thing is, that book is a “novel of ideas” in that old-timey SF way, but its idea wasn’t really that deep, novel, or interesting, so it felt pretty basic. But the sequels take that idea and run it through cycles of elaboration, piling on more and more ideas, each one a “oh, you thought you understood the universe, but wait there’s more“ moment. By the end of the third book, there’s so much going on that you could arguably make the criticism that it’s overstuffed with too many SFnal concepts.
But it’s not a criticism that I’ll make, because I liked it a lot. It is still very retro-style throwback SF, but it’s doing a thing that I love—following a society through deep time as it evolves and changes—and doing it well. It’s fun, albeit in a bleak way.
The criticism I’ll actually make is that the third book has a running theme contrasting “masculine” decisiveness and aggression with “feminine” pacifism and nurturing, which… well, if you’re going to mine old-timey SF for cool plot structures, go for it; but the antiquated gender role bullshit really doesn’t need to come along for the ride.
Anyway, if you like SF of the old-school with space shit and technological development and aliens and civilization-defining crises and all that, and you don’t demand naturalistic dialogue or three-dimensional characters and can look past some weird retro-sexism, this is what you’re looking for.