This is definitely the first film ever made to introduce the SF idea of replicants (here called "Nonlinears") , android robots who are almost indistinguishable from humans. Sure , you might have had movies featuring androids before but not in sense of the term you would describe the characteristic features of Blade Runner's replicants that have become a staple of pop culture.
The story in short is about a space pilot who has to commandeer a ship to Saturn to launch some probes, with his crew being an assorted mix of humans and replicants. With no knowledge provided of who is who, he has to ensure the mission's success which will influence the UN's decision whether replicants should be mass produced or "retired".
There are a lot of Blade Runner vibes in terms of the ideas and themes discussed. How do you actually define human traits? Can human foibles actually have purpose? Would you consider yourself superior to humans if you are made physically stronger but as a factory product with an imposed life cycle( no real sense of growing up from child to adult)
In terms of pacing, this movie oftentimes actually feels like a Hollywood action film of the era, very fast paced instead of vast stretches of time devoted to just dialogue between two-three characters, as is often the common perception of these Cold War era Eastern films by the West. If characters do talk, it's not usually about long expositions or ruminations but quick exchanges to move the plot along.
The special effects are passable for the era. The space ship's interiors are well designed . However, the miniatures could have used more detail. At times, when the space ship is shown moving through space, it looks more like a gas cylinder suspended by rope than an actual miniature that was sculpted by an artist. Also, for some reason, for showing the lift off of the rocket from Earth, they chose to use NASA stock footage which is glaringly evident in the film quality differences between the NASA archive shots and regular film shots . At the very least, they could have done some post production to try to ease out these differences.
Despite all of the film's shortcomings, the film succeeds in an entertaining suspension of disbelief in the light of the pacing and especially the good performances . I think all the actors were well chosen for the characters they played.Sergei Desnitsky is likable as Commander Pirx. Also noteworthy is Aleksandr Kaydanovski ,who also appears in Tarkovsky's Stalker.
In conclusion, this is definitely a film to check out if you are a Blade Runner fan or simply want to explore the vast library of Soviet Polish films