I’ve seen some very interesting Soviet films on Youtube and if anyone else wants to see what I’ve seen so far, here is the list (not all of these are in Russian):
Vladimir Chebotaryov and Gennady Kazansky, “Amphibian Man”*
Alexander Dovzhenko, “Aerograd” (no English subtitles though)
Alexander Dovzhenko, “Arsenal”
Sergei Eisenstein, “Alexander Nevsky”
Fyodor Khitruk, “Vinnie Pukh” / “Vinnie Pukh idyot v gosti” / “Vinnie Pukh i den’ zabot”
Mikhail Karyukhov and Alexander Kozyr, “The Sky Calls” aka “Call of the Heavens” (Russian name is Nebo Zovyot)*
Pavel Klyushantsev, “The Planet of Storms” / “Planeta Bur’ “*
Georgy Kropachyov and Konstantin Yershov, “Viy” (1968 horror film based on Nikolai Gogol’s short story)
Konstantin Lopushansky, “Dead Man’s Letters” (a poor man’s “Stalker” – Lopushansky assisted Tarkovsky on that film)*
Risto Orko and Alexander Ptushko, “The Sampo”
Sergei Parajanov, “The Color of Pomegranates” aka “Sayat Nova”
Sergei Parajanov, “The Legend of Suram Fortress”
Sergei Parajanov and David Abashidze, “Ashik Kerib”
Marek Pestrak, “Pilot Pirx’s Inquest” (Polish-Estonian production)*
Yakov Protazanov, “Aelita, Queen of Mars” (1924 silent film)*
Yevgeny Sherstobitov, “The Andromeda Nebula”*
Dziga Vertov, “Man with a Movie Camera” (1929 silent film)
Vasily Zhuravlov, “The Space Voyage”*

The cartoons by Khitruk are a Winnie-the-Pooh trilogy based on the original A A Milne stories and all three cartoons are much, much better than the Disneyfied version of Winnie of Pooh.

The asterisked films are science fiction films and with the exception of “Amphibian Man” and “Dead Man’s Letters”, all are space travel flicks of a mostly pro-Soviet bent. The set designs on some of these films can be quite astounding for their time (most of them were made in the 1960s). I do recommend seeing some of these films even though the plots and acting look clumsy because they give an insight into Soviet attitudes about space travel and they emphasise co-operation and the advancement of scientific knowledge rather than competition and blasting aliens which seem to be the lot of most Hollywood sci-fi space operas.

There are quite a few Dovzhenko films on Youtube but not all of them have English subtitles.