One of the most celebrated, influential and expressive pictures of the Czechoslovak New Wave cinema, and although on its surface it is a family-friendly, light-hearted, colourful fantasy dramedy film, in its core the film is subtly a political allegory for authoritarianism, false appearances and hypocrisy, with the cat symbolic being able to see the people of the town for their true colours.

Instead of posing as a model, Oliva recounts a story of a cat with sunglasses – whose eyes revealed the true nature of the human condition through colour.

In the midst of a circus act coming to town, Robert's cat goes missing and he is led to Diana – an actress who is part of the performance.

Whilst the cat is later found by children in the woods, the school servant snatches it and attempts to have it killed – orchestrated by Charlie.

Defeated, Robert walks alone back into the town square, only to be greeted by the children, who are holding art and paintings of the cat.

James praised the film's photography but found fault with Jasný "overdoing every effect", concluding that The Cassandra Cat "fell short of the believable fantasy it needs to live on as more than a curiosity".

Maintaining the film's original colour scheme proved to be a challenge due to its "multi-coloured experimental celluloid techniques".