It's somewhat impossible to talk about this novel without also talking about the long shadow cast by the 1972 film adaptation by Andrei Tarkovsky. Whenever I bring up the movie in discussion, I unmask one or two Lem fans who always, without fail, bring up how the book is better. I politely nod and mumble about how I should read it, while internally recoiling in skepticism. That Stanislaw Lem? The author of the Cyberiad? Now, having finally read it, I can confirm my gut feeling was right. I should have known I was being memed.
Now, it's by all means, not a bad story. But I wouldn't really call it "better". It's certainly different from the movie, which took a lot of liberties, partially due to budget constraints, and 1970s special effects technology being entirely insufficient to portray the strangeness of the alien ocean, or the floating station levitating close to its surface. The filmmakers solved it by turning the station into a more conventional orbiting outpost and simply ignoring the pages and pages of autistic descriptions of the bizarre forms spewed forth by the alien intelligence's strange creative powers (aside from the one part with the pilot describing his encounter with the giant "form" in front of a committee, which is one of the most powerful moments in the movie, despite it just being a guy monologuing in front of a camera). It turns out none of the core story requires the station to be physically next to the ocean, anyhow. I always wondered how the visitors reached the station from the planet surface, and expected the book to be more grounded somehow, but how they got inside is left as a mystery here, as well. I also prefer the movie's bleaker, more enigmatic ending note.
I have to voice how much I dislike the whole concept of the station being held aloft by anti-gravity repulsor lifts. It's some kind of a cousin of the Cloud City. Come on, it's a planet both with an ocean and an atmosphere. If this had been written by Arthur C. Clarke, the station would have been either some kind of a blimp, or just a regular boat. But no, we must smuggle antigravity technology into a story that doesn't need it. Of course, the movie kept the station's disc shape, implying generated gravity, but that's a pretty common trope in the live action medium and they obviously didn't have the budget for a 2001 style rotating wheel station. It's easier to ignore.
While Lem has a talent for describing the strange in visually evocative ways, I feel in the case of this story, he ends up wasting the reader's time and patience trying to explain something that fundamentally cannot be explained. The entire premise of Solaris is absurd. A sentient ocean is absurd. An alien intelligence creating homunculi from the memories of a station crew is absurd. When this is the matter your story is composed of, it's best to not even try to pretend it's scientific. It's basically a spooky ghost story in space. When stripped of Tarkovsky's genius cinematography, it's an above average Star Trek episode. Using fewer words makes the mystery more compelling.