Francesco Quario’s review published on Letterboxd:
Although there are many live-action films that are able to visually convey the physical sensation of dreaming (Meshes of the Afternoon; Blood of a Poet; Inland Empire to name but a few), only the endless possibilities of animation can truly capture that peculiar oneiric state.
Waking Life's use of heterogeneous styles, all of which have imprecise contours and lines that are constantly shifting and moving, effectively depicts the sense of impermanence and floatiness that accompanies vivid dreams. I've never been a lucid dreamer, although I approached that threshold several times, but the particular weightiness of the animation and rhythm of the camera movements still reminded me of many of my dream experiences.
The film uses this stylistic device to tell a story about the boundaries between dream and death designed to make you question the veracity of concepts such as reality and time. However, the true aim of the film is to represent a series of Socratic dialogues about the most disparate philosophical topics.
The scattershot nature of these dialogues works well in tandem with the dream structure, which may also serve to excuse the unnaturalness of some of the deliveries. Some of the dialogues will keep you engaged, others will bore you; some will have you nodding in agreement, others will strike you as pretentious. I see this as a feature of the film, rather than a flaw, since the lack of consistency between each scene is bound to let you come up with your own opinions regarding the plethora of arguments presented.