Uncommonly stylish but equally silly, M. Night Shyamalan’s follow-up to the disappointing “Unbreakable” is, as one character observes off-the-cuff about halfway through, basically a modernization of H.G. Wells’ “The War of the Worlds,” though done on a far smaller canvas (a single family is the focus) and filmed in the writer-director’s characteristically glistening, almost metallic palette of subdued colors. It too concerns an alien invasion of earth, and it further resembles Wells’ work in basing its denouement on the workings of providence. In the latter respect, though, it’s less true to the vision of Wells, who took a determinedly secularist approach (the clergyman in his narrative is rather a fool, and the providential intervention is basically a natural phenomenon) than to the more religiously uplifting finale in the George Pal-Byron Haskin filmization of 1953 and to Shyamalan’s own sensibility as well. His previous films have all had a distinct streak of mysticism (and even, in the case of “Wide Awake,” blatant religiosity) about them, and so it’s not remarkable that “Signs” should try to raise questions about faith in the face of such a crisis. In truth, however, his treatment of the subject is pretty shallow, even by Hollywood standards; the main character, tortured by spiritual doubt, may be called Graham, but his dilemma is portrayed with nowhere near the subtlety and power with which his namesake, the novelist Greene, would have rendered it.

The picture opens none too promisingly, with the Hess family in rural Pennsylvania–widower-dad Graham (Mel Gibson); his younger brother Merrill (Joachin Phoenix); and darling urchins Morgan (Rory Culkin) and Bo (Abigail Breslin)–frightened by the appearance of crop circles in their fields. (Crop circles! Oooo, scary!) Shyamalan, employing his admitted skill at creating an unsettling mood, gets some easy shocks in this portion of the flick through cheap tricks like having barking dogs leap at characters from out of frame; but he mostly attempts to unnerve us by showing the family members disturbed by noises and movements in the swaying stalks of corn surrounding their house. (Unfortunately, anyone who’s seen one or more of the wretched “Children of the Corn” movies is likely to find this footage more risible than upsetting.) Gradually he unfolds the clan’s difficult history–Graham has recently given up his calling as a minister, having lost his faith after his beloved wife’s death in a traffic accident (an event which has also deeply affected the kids), while Merrill is a failed minor-league baseball player nursing the possibility of joining the army to escape what seems a hopeless future. Their personal difficulties soon pale into insignificance, however, when the crop circles prove to presage an alien invasion of earth, which we hear about from a distance through news reports (more shades of “War of the Worlds,” the Orson Welles version this time) and experience on a local level when their house is targeted. Before long the film has turned into a rustic version of “The Panic Room,” with the clan huddled in an old coal cellar, unseen hands banging at the door and messing with the knob, and sweet little Morgan gasping for breath (naturally, he’s left his asthma medicine upstairs in all the tumult). All this might have generated more tension if it weren’t so damned familiar.

What works best in “Signs,” in fact, isn’t all the moody, shiver-inducing stuff that’s supposed to be Shyamalan’s stock-in-trade but the comic moments, which are surprisingly frequent. The family is presented in arch, oddball terms, almost like a bizarre version of a typical sitcom brood, and even when the gags are obvious (as in the kids’ donning of tin-foil hats to prevent alien mid- reading), they’re given a sufficiently deadpan spin to elicit a smile. Gibson, in particular, makes the dad a singularly strange, quizzical figure, vaguely otherworldly himself; and Shyamalan accentuates the air of peculiarity around him by not revealing his ex-clerical status straight on, making one think he might be the leader of some weird cult when outsiders inexplicably address him as “Father” in the early going. As a performance, though, it’s a highly mannered, stilted turn, more stunt than anything else. Phoenix plays the brother as slightly dense but lovable, an admitted cliche but one that scores some points. The children are fine–Shyamalan has always shown an aptitude for drawing the best from youngsters–though the script uses them too often as comic pawns or tools of emotional manipulation. The director himself, who’s done cameos in his previous films, takes a longer role here as a troubled veterinarian; on the present evidence he’d be well advised to stay behind the camera. Points are due, though, to the rich, dextrous cinematography of Tak Fujimoto and the supportive score by James Newton Howard, who provides something more edgy and insistent than his usual sonic pabulum.

What really sinks “Signs,” though, is Shyamalan’s predilection for adding a customary note of mysterious profundity to his narratives. The entire plot thread about Graham’s loss of faith is hackneyed at best, and the revelation of it through portentous flashbacks is a ham-fisted melodramatic touch. Then there’s the ending; Shyamalan seems to believe that he’s now obliged to provide a concluding twist that will surprise us all, but the one he contrived for “Unbreakable” was merely a limp trick, and here the effort to resolve both Graham’s spiritual quest and earth’s larger problem by offering a dumb variant of Wells’ original close falls flat.

So “Signs” is yet another Shyamalan product that creates a creepy ambience but proves too simpleminded to carry the heavy load of meaning he imposes on it. Despite its obvious craftsmanship, the picture fails to generate much suspense, nor does it ask searching enough questions to justify its pretensions. Its advertising tagline is “Don’t see it alone,” but the better advice is probably “Don’t see it at all.”