The movie is straight follower of classic existentialism (impressionistic).
You should see this picture only in theatre. Because it has so consistent photography. Contrasts and color are chosen very good.
EVERY frame is made to perfection. When frame moves, I relax absolutely and enjoy every single shot of this movie. Though I understand that Alexei made gigantic work. Only after theater I checked - they indeed were shooting with some interruptions for over 4 years.
If you know a little how cinema makers work - it is definitely for you to enjoy. Absolute perfection.
Movie has preface words: "Aligning and positioning do not exist. Picture is relation of contrast, even just relation of black and white" (Paul Cézanne).
Action prevails over motive. Action exists as itself, no randomness, because everything will repeat itself. No matter what happened as it will happen again and were happening before. Atmosphere prevails over plotting. Metaphor is strongest move.
I think central in there is metaphor of Post Cold War world. Compare age of twenties to what we have now. Because of that author is using 72 kWatt house illumination (house of artists episode) to make straight passing to "shining twenties".
In some episodes there is interesting notions about "90-es OD feeling" and "80-ies fall of USSR era". And all this OD world is compared to our, is frozen just because nobody has balls to move it.
Also I see many relations to works of Anton Chekhov. Most notable is relation to "missing person" genre. Just check out "The Cherry Orchard", everything is related to world of that play.
Though I have some negative, which is mostly about my opinion. I would like some clarifications in middle of movie. May it is due to interruptions in production of movie. Because of it you can notice difference between first and second halves.