I feel like the tricksters in this film (or someone much like them) appeared again a year later in Nataliya Golovanova's excellent "Sweet Porridge". Which is odd, as the two films share no crew except for two animators (Aleksandr Dorogov & Violetta Kolesnikova) and the script editor Tatyana Paporova.

Sometimes there were "borrowings" like that in Soyuzmultfilm at the time.

I have watched this movie on Vietnam Central Television since I was very young, although I did not know the name of the movie at that time and only watched it on black-white TV. However, the child's brain remembers the fanciful scene in the circus for a long time, so it will surprise you when you watch it again later. That, I think, is the psychological success of the filmmakers.