This book has many layers. And what I find particularly nice about it is that it's fully enjoyable regardless if you stay on the top layer, enjoying a smooth and quite humourus ride, or if you choose to go deeper to engulf yourself in the more multifaceted symbolisms.

When being close to finish the book I was firmly settled for a 4/5 rating, but after reading the very interesting afterword, which provides additional context and tells the story of the early work and revisions that lead up to the finished book, I decided that it was worth of a 5/5.

I have to say that there were parts of the intended symbolism that I really did not fully understand, or interpreted differently, on my readthrough. But that indeed seems to be part of the book's identity, as Boris Strugatsky also appears to imply in the afterword:

"And the question is this: Should we, the authors, consider it a failure that an idea that helped us make the novel multifaceted and deep was never really understood by the reader? I don't know. I only know that there exist many interpretations of The Snail on the Slope, many of which are totally internally consistent and in no way contradict the text. So maybe it's actually a good thing that this work generates very different responses from a wide variety of people? And maybe the more interpretations there are, the more reason there is to consider the work successful?"