Psychological Horror at its very best10/10
One might argue Roman Polanski's Rosemary's Baby is not a horror film, since it lacks almost everything you'll find in almost all of them: shock moments, vampires, werewolf, serial killers, even blood. The most graphic scene is a nightmare sequence that displays a rape scene so stylized it isn't actually disturbing. But one might also argue that Rosemary's Baby is a horror film in its purest form, since it doesn't depend on all those gimmicks to create its atmosphere. I prefer the latter point of view.
So what is happening in this film? Rosemary and Guy Woodhouse move to a new apartment. Their neighbors are Roman and Minnie Castevet, an elderly couple. Although they are very friendly, there is something strange about them - the sounds that come from their apartment, the fact they remove all the pictures from their walls when the Woodhouses visit and other things like that. While Rosemary tries to keep a certain distance from them, Guy is very fond of the relationship to his new neighbors, and especially Minnie becomes more and more obtrusive, especially when Rosemary finds out she's pregnant - she recommends her another (better, as she says) gynecologist's and mixes a (healthy, as she says) herbal drink for her every day.
The pregnancy, however, develops rather unpleasant: Rosemary keeps feeling pain in her stomach and she becomes thinner (Pregnant women are supposed to gain, not lose weight, a visiting friend observes), and when the pain doesn't stop after several months, she begins to believe that her neighbors, her gynecologist's and even her husband conspired against her and want to harm the baby she's carrying.
All this is told by Roman Polanski in the perfect tone; the mood for the entire film is already set during the opening credits when we hear that weird lullaby, sung by Mia Farrow. And a lot of strange things happen throughout the entire film: Guy and Rosemary are told by Hutch, a friend of theirs, about the horrific past of the house they're now living in, a young girl that lives with the Castevets commits suicide (really a suicide?), Guy, an actor, gets the role he wanted so badly after the contestant who was originally supposed to play it turns blind, and Hutch, who might have found something out that would help Rosemary, suddenly is in a coma and dies three months later; all these (and a few other) events are precisely dosed by Polanski to draw us more and more into the film, while he makes sure on the other hand that the film doesn't become absurd. And he manages to give the film an ending that works, makes sense and is observant, slightly (but only slightly) funny and very disturbing, all at once.
Rosemary's Baby also contains two of the most memorable performances ever: Mia Farrow is haunting as Rosemary Woodhouse. She looks like she is physically suffering from her pregnancy and close to complete despair. And Ruth Gordon is amazing as the curious Minnie Castevet, always friendly, but also giving you the feeling that, hidden behind her generosity, she actually follows her own, obscure motives. If you have a helpful elderly female neighbor, you'll see her with other eyes once you've encountered Minnie Castevet. So, if you think a real horror film needs shock moments, vampires, werewolf, serial killers or at least blood - watch Rosemary's Baby and you'll change your mind.