Just watched this last night, I can't think of any better reason for the existence of the internet. This is such an excellent film, on so many levels, and were it not for the internet and this slippery beast of electronic media distribution, I would never have seen or heard of it. In Russian, from 1986. IMDB shows a Japanese release in 1991.
After you've watched it, and asked yourself where it's been all your life, and how people on Earth ever know who to squat to and how many times, next ask yourself if you know of a better way to get gems like these out and about.
Just so you are forewarned, the film is a bit longer than average, although it does have an intermission, complete with visual break, calming music, and glossary of alien terms. Since YouTube has it in sections, that won't be a huge problem, although they may have started a thing that makes the next section start playing automagically when one ends, so keep an eye on that. It's about 2h10m, all told.