The Czech film O slavnosti a hostech (1966) was shown in the U. S. with the translated title A Report on the Party and the Guests. It was co-written and directed by Jan Nemec.
This movie starts off innocently enough. Several friends are enjoying a picnic in the woods. Suddenly, about a dozen men interrupt the picnic, and, politely, but firmly, escort the group to a new location. One of the picnickers is roughed up, but no one is badly hurt.
Then, another man, who is in charge, invites the picnickers to an outdoor wedding party. The whole situation is threatening, but not terrible. Much is made of one of the picnickers who decides to leave, but the other picnickers decide to stay to enjoy the party.
This film was immediately banned when it was completed. The government knew that it was an implied attack on the authorities who ruled Czechoslovakia with an iron fist. It was released during the Czech Spring period, but then banned again after the Russian tanks rolled into Prague. It wasn't released until Soviet rule ended.
This was a difficult movie to enjoy. After the first few minutes, the plot was very tense. On a more basic level, we saw the film on an old VHS cassette, which was in bad condition, and may have been a duplicate. The subtitles were often white on white, so we missed some of the dialog.
The film has an IMDb rating of 7.1, which is pretty good, all things considered. I rated it 8 for the movie I would have seen if I'd watched it on DVD.