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.
Leben des Orest Leben des Orest ("The Life of Orestes") is a grand opera in five acts (eight scenes) with words and music both by Ernst Krenek. It is his Op. 60 and the first of his own libretti with an antique setting. The score is inscribed with the dates of composition: 8 August 1928 – 13 May 1929, and includes indications of recommended cuts made for the first production. It premiered at the Neues Theater in Leipzig on 19 January 1930, and opened at the Kroll Opera House in Berlin in early March of the same year (Leichtentritt 1930, 366).