This novel felt underbaked to me. It has some interesting ideas, but none of them are developed to their potential. The alien biology and psychology of the visitors isn't developed enough to be the feature of the novel. There are a lot of scenes where people sit around in conference rooms and talk about the possible consequences of the aliens' arrival, but most of those consequences never eventuate and the ones that do aren't depicted in a way that makes them feel meaningful. The characters, even the ones who exist for more than just to state things for the reader's benefit, never quite come alive, and they all end the novel as the same person they were at the start. There are some gestures toward an analogy between the visitors' behaviour and the behaviour of the Europeans who colonised the new world, but it never comes to anything, and the same with any of the other hints of having something to say about real-world issues.

There's a scene about two thirds of the way through where a character sums up the visitors' behaviour to that point by saying that they've occasionally been a bit of a nuisance but haven't done any real harm, and I found myself thinking that that could serve as the summary of a novel that had been fitfully intriguing but never blossomed into anything really dramatic or involving.

A few chapters after that, something finally happens that promises real drama, but in the end it all fizzles out into more scenes of people sitting around talking about what might happen.

(There's also an ambiguous twist thrown in about thirty pages toward the end that might have passed muster as the sting in the tail of a shorter story but in this case goes nowhere, doesn't fit with the tone of the rest of the last thirty pages, and just makes the ending feel even more like a bundle of loose ends than it already did.)