I've seen this a number of times now so it's difficult for me to remember having trouble getting into the stylised form of acting and by 1944 dated expressionistic cinematography that other viewers might have. First time of watching it was on UK TV over 20 years ago with Part 2 and a documentary called Part 3 containing the remaining extant scenes, and I loved it. I'm dead against arty farty pretentious movies and am always aware that being obscure does not automatically make a film a classic, but this really is a classic of its kind. It was Eisenstein's best work (imho) a rallying call to all of the disparate inhabitants of Mother Russia to work and fight together, which was ordered by Stalin and who was pleased with the similarities I bet he was on tenterhooks waiting for Ivan to go insane though.
Ivan is crowned Tsar of all the Russias and proceeds to drag the country into the 16th century, disposing of external enemies in the form of Tartars, starting a long war against Livonia and limiting the influence of the antagonistic aristocracy, the boyars. The acting is intensely melodramatic, with endless sinister sidelong glances taken from acute camera angles and Ivan's pointy beard shown to good advantage, which to people not paying much attention can probably be mirth-inducing. But this was pulse-quickening propaganda for the new Russian working class to comprehend, not Artheads decades later - Eisenstein did it so memorably that like Potemkin it's still spellbinding today. Otoh he borrowed extensively from Snow White too for some of most incredible shadowy images in here, and his whole technique hadn't moved on from silent film. The use of the b&w nitrate film, costumes, sets and angular ugly faces are wondrous to behold and Prokofiev's stirring music glues it all together triumphantly.
All in all, a knockout film with faults but which still defies and will survive all criticism.