Quite a charming, optimistic film that shows a slice of typical daily life at the time through a child's perspective, but should be interesting for adults too (it's not aimed at them, but it doesn't insult its viewers' intelligence like some children's films). It feels kind of like Roman Kachanov's later films to me.
It seems that by this point, not too much was left of the original "Firefly" concept, other than "collection of shorter stories aimed at children taking place in a contemporary location". Unlike the previous ones, there's no central narrator (firefly or otherwise), and the stories are NOT adapted from previously-released children's books or comics.
It's kind of neat that despite there being two directors (each one responsible for one story, I assume), the film is stylistically unified and the first story flows fairly smoothly into the second.
The directors are also the art directors, but actually, the art style seems heavily inspired by the 1961 "Big Troubles" from the Brumberg sisters.