"A warning: Despite the state-of-the-art visual effects and Scott's remarkably comprehensive use of the syntax of film, Scott seeks to entertain you by the brutally primal tactic of reaching into your gut and squeezing your adrenal gland: There's an awful thingie there in the dark, and it gets people, and you have to watch it as it does. The filmmakers have come up with some images that are sheerest nightmare. The film earns its shudders honestly: Scott is too talented to need gratuitousness as an aid. We are repelled more by the idea of what's happening than by simple excess of repellent images. Still, even while you acknowledge that the filmmakers are scrupulous, sitting with your arms wrapped around your head because you can't watch the screen may not be your idea of a good time."