What a Flash! (1972)

The producers of this French film took approximately 100 people, put them on a soundstage and had them improvise this film based on the premise that they are on a spaceship escaping from the dictators of earth and only have a few days to live. Improvisation is a dangerous art-form; unprepared amateurs invariably come up with gross caricatures when challenged to improvise. The actors' choices in this film include an allegorical pageant of the life of Jesus, a marriage, an orgy, and some genuinely affectionate moments. Nonetheless, as an experimental effort in large-group improvisation, the film is instructive. - Clarke Fountain, Rovi

Unfortunately the movie What a Flash! is not yet available on HBO Max.