This is a tense, atmospheric thriller, without much humor. It is more like "Vertigo", "I Confess", or "The Birds" than "North By Northwest" or "The 39 Steps". Instead of humor, Hitchcock concentrates this time on carefully constructing the world of the Verlocs, the family at the center of the film. The setting, in a movie theater where the family works and lives, is an important part of the themes and questions explored in the film.
The characters are constantly walking in and out of the theater while movies are in progress, or discussing the movies being shown as they go about the main actions of the (actual) film. The obvious themes of appearance and reality parallel the lives of the Verloc family, and especially Mr. Verloc (Oskar Homolka) whom we know from the beginning to be a terrorist, albeit an amateurish one, and not the mild-mannered family man he appears to be. The settings of Verloc's meeting with his co-conspirators, an aquarium and a bird shop, are also carefully chosen to demonstrate the contrast between the everyday appearance of the terrorists and their actual agendas. Besides the obvious implication that such persons may be those we would not suspect, there is also the strong suggestion that these conspirators do not themselves realize the serious nature of the game they are playing. Certainly Verloc himself quickly realizes that he is in over his head, and he tries desperately to get out of the fearsome responsibilities he has accepted.
Hitchcock buffs will enjoy watching the film repeatedly to catch all of the carefully crafted detail, and to enjoy the trademark Hitchcock touches. There are two particularly riveting sequences. One occurs when Verloc sends his wife's young, unsuspecting brother on a dangerous errand, leading to a sequence of excruciating tension. Hitchcock later said he should have ended the sequence differently, and many viewers might agree, but what happens is in keeping with the themes and plot of the movie, and the suspense sequence is also masterfully done. Also well-known from "Sabotage" is the sequence when Mrs. Verloc (Sylvia Sidney) learns the truth about her husband's activities, and the awful consequences of his latest plot. There is first a touching sequence in the theater, when the Disney movie playing on the screen first provokes Mrs. Verloc to involuntary laughter, then to deepened sadness when it too closely parallels her own experience. Then there is a tense, famous scene at the dinner table, filmed as an absolutely masterful montage by Hitchcock.
These scenes, and the finely crafted atmosphere of "Sabotage", make it worthwhile despite a few small faults, and despite the possibility that many viewers will not be comfortable with some of the plot developments. Watch it at least once if you are a Hitchcock fan, or if you like spy stories or thrillers.