I think this is actually closer to a 3.5 for me, but let's bump it up to 4 for the refreshing perspective and imagination in the worldbuilding. I'd read the first story a while back, but just picked up the collected trilogy and read the remainder, so this review is for the series as a whole.

I had some problems with the initial novella because it's presented as science fiction but has so many elements seeminly of pure fantasy that didn't seem well explained at all - such as why on earth would the Meduse - whose technology seems to far surpass humanity's, and who can literally change the genetic structure of Binti with apparently no effort at all - why do they magically seem to be healed by the mixture of clay and perfumed oil that Binti's people cover their bodies with. On reading further into the trilogy it becomes clearer that this really isn't a science fiction series, but instead a series about the personal growth of the main character, told through a blend of science fiction and fantasy. It's the grey area of "any technology sufficiently advanced is indistinguishable from magic", and maybe some of it can be justified as advanced technology, and other parts cannot, but from the reader's perspective it's hard to say for sure. Suffice it to say there are elements that appear to be pure magic, and some very deus ex machina solutions, but that's not the point of the series. The key focus of this series is the growth of Binti a a character and how she fits into and changes the worlds she's part of, and the trilogy does a decent job of bringing this home.

I like the characters, particularly the alien ones; I like the alien worlds; the wildly diverse environment of the university reminds me a bit of the Chanur books by C.J. Cherryh where wildly different alien species somehow manage to get along and interact even when they can't even always share the same atmosphere. It's an optimistic view of a highly diverse future that I'd love to dream is possible one day even though I highly doubt it ever could be. I like visiting this vision of the future and will pick up any future Binti novels that come out. I'd particularly like to see more of the university and other non-human worlds.