Growing up, my parents read the Neznaika stories to me. As I got older, I read them myself. It was my favorite story as a child. This movie is by far the best adaptation of the stories that I have seen so far, and it works whether or not you read the books. It is a delightful take on the children's stories, and despite the Soviet-era connotations that the stories carry, they nevertheless remain timeless, teaching our kids about friendship and compassion while also being incredibly entertaining and fun.
For the unfamiliar, Neznaika is about a group of little people (karatishki) who live in peace and harmony on earth. They are "little men" but are essentially children: the girls like the boys, and the boys just want to go on adventures. Neznaika himself is the main character (in Russian, his name means something like "Know-nothing.") He is ignorant and boastful, but at the same time kind-hearted and lovable. All the other characters also have names that tell you what they do.
This movie has many of the same wacky adventures that made the books so popular. Literal bottle rocks, hot air balloons that run on soda, and of course the main attraction: our friends going to the moon and encountering a new society that is very different from the one on earth. Needless to say, this society does not live in peaceful harmony.
In conclusion, I highly recommend this movie whether or not you have read the books.