"Ironically, "Alien " is not a bad movie. In fact—here's the rub—it's too interesting to make an exciting summer flick. At the core is a promising tale written by Australian filmmaker Vincent Ward, who made "The Navigator: An Odyssey Across Time," an often brilliant, time-hopping saga about medieval men journeying into the 20th century. His "Alien " is woven out of the same classic sci-fi yarn. The prison is a Middle Ages-type institution, with gaunt-faced, monastic characters in robes walking through dark, twisting corridors bearing candles."