The two acts of the play form a contrapuntal structure. Act 1 is set in British colonial Africa in Victorian times, and Act 2 is set in a London park in 1979. However, between the acts only twenty-five years pass for the characters. Each actor plays one role in Act 1 and a different role in Act 2 - the characters who appear in both acts are played by different actors in the first and second. Act 1 parodies the conventional comedy genre and satirizes Victorian society and colonialism. Act 2 shows what could happen when the restrictions of both the genre of comedy and Victorian ideology are loosened in the more permissive 1970s.
Cloud Nine contains elements of expressionism and absurdism, but also relies more on realist conventions than Churchill's later plays. The play uses controversial portrayals of sexuality and obscene language and establishes a parallel between colonial and sexual oppression. Its humour depends on incongruity and the carnivalesque, and helps to convey Churchill's political message about accepting people who are different and not dominating them or forcing them into particular social roles.