I think this was a very strong beginning to Marchenkova's directing career. It's has lots of variety and changes in mood, not to mention animation techniques and visual styles, and it already seems to have most of the elements that she would draw from in one way or another in her subsequent films. It feels both pretty grounded (in how carefully the attic and the two character's interactions are shown) - a bit like Yuriy Norshteyn's films - as well as phantasmagorically inventive - a bit like Robert Saakyants' films.
The only real downside I see is that it rather relies for its humour on the viewer being familiar with the characters and stories being visually referenced, and that will only be true for those above a certain age within the (former) Soviet cultural sphere. Younger children will not have been exposed to the stories yet, while in other places even older viewers wouldn't know them. In North America, for example, some of the stories are also fairly well known, at least by reputation (the genie and flying carpet, Baba Yaga and her hut, Santa Claus, the Pied Piper, Zmey Gorynych) but others aren't well-known at all (Alyonushka and her brother, the frog traveler, Doctor Aybolit, Grandpa Mazay, the 3 wise men, Tsar Saltan) - I'm not quite sure about the wolf fishing with his tail or about Thumbelina.