This is my favorite Hitchcock film. Free of all the gloss and artifice of his later (though still admirable) works, it has a masterful visual style informed by his work in silent film, and a powerful emotional impact. The film expresses things (feelings, ideas, mood, associations) that could never be expressed through any other medium. In this way it is purely cinematic. It demands more attention of the fewer to catch all of the details, but as is his trademark, nothing is wasted and every element works harmoniously in service of a powerful vision.
A better adaptation than Annihilation but still the film is insufficient to the story. I feel like this could have been a great limited series, maybe six episodes. I did not like the way it was directed and edited - too many flashbacks, overly sentimental at times and too much ellipsis. I see how they were trying to mirror the psychological state of the protagonist but this requires knowing when to employ these devices and when to pull back and let the narrative unfold. It is out of balance and pushes the viewer out of engagement with the film.