Agatha resides at the intersection of an experimental art piece and a horror movie. Knowing that, you know how to proceed with this film. Agatha is visually stunning but ultimately difficult to process at times. It is mesmerizing and dreamy and entirely devoid of dialogue. There are maybe ten spoken lines in the entire film, and all the exposition in the story is delivered visually with layers of allegory painted on.
The movie appears to have been run through a digital Rotoscope effect. A live-action film that has been run through a heavy digital filter to deliver a gauzy oil painting comes-to-life atmosphere. The film is loaded with visual detailing, alternating between a Victorian curio of collected history and a completely blighted urban apocalypse as the primary settings for the film.
Agatha asks a lot of the audience. Themes of sickness, grief, revenge, forgiveness, shame, decay, and ritual all are on display here. The storyline is not linear either, with looping scenes and flashbacks that will test your attention. I would get lost from time to time, and if you happen to watch this with someone who will ask questions during a movie, you should probably consider watching this alone, because you will be having to describe a dream in midstream, and it will be difficult to explain.
Is it fun? No, not really. It is definitely an intellectual piece, and certainly not for everyone. (See some of the other reviews here.) But, if you are the type of person who can sit in front of a Hieronymus Bosch and find dark meanings, this movie will be your bag.