Which opera, if any,  Venus and Adonis or Bluebeard's Castle has more acts ?
Venus and Adonis (opera) Venus and Adonis is an opera in three acts and a prologue by the English Baroque composer John Blow, composed in about 1683. It was written for the court of King Charles II at either London or Windsor. It is considered by some to be either a semi-opera or a masque, but "The New Grove" names it as the earliest known English opera.
L'écume des jours (opera) L'écume des jours (English: "The Foam of Days") is an opera in three acts (14 scenes) by the Russian composer Edison Denisov. The French (also German and Russian) text is by the composer based on the novel of the same title by Boris Vian. It was composed in 1981.