For a professional review, check out Dargis in the New York Times. I agree with almost all of it and want to add my two cents because this is a film I wish to remember. (Denis Villeneuve, by the way, also directed Sicario, which is entertaining but fails badly). Arrival is ambitious and profound and comes close to synthesizing a litany of complex elements into a full story. It is immensely enjoyable.
For me the film has rough loose ends with respect to character development, philosophy, science fiction (i.e. alien life and technology) and much else. It is, however, well crafted and devilishly provocative. In the end, though, the filmmakers very nearly drown all of this with a maudlin leitmotif of a mother-daughter relationship. Visually, its use of metaphor and symbols is dazzling. I will never forget aliens instantaneously communicating complex screeds with inky secretions of circular symbols. This rivals the stuff in Star Trek’s The Next Generation’s Darmok. (See also this take on that wonderful episode).
My favorite thing about the film is its reflection on time, linguistics, and memory. There is a thesis here on how these neither operate discretely nor linearly, that we have power individually and collectively to shape multiple existences, histories, realities, and even universes. The stuff on memory was Proustian, particularly the lush sequences of Louise at home with her child that seemed to diminish time and space, flitting backward and forward sometimes, and dangling at others. We live, according to the story, in the past, present, and future all at once and we communicate not only with ourselves and others now, but also across time, space, and existences utilizing our minds, our voices, our pens, and our sentiment.
The aliens, named Abbot and Costello by the scientist and linguist, encourage us to remember forward and backward, to live all at once rather than discretely. They teach this Quixotic lesson and its implications to Louise. I wonder, though, if the film succeeds in getting this across to the masses?