What’s most admirable about onetime X-Files producer R.W. Goodwin’s Alien Trespass, a simulacra of the ’50s flying-saucer flick, is its bypassing of the wink-wink condescension that usually defines screen flashbacks to the Eisenhower era. Its problem is the absence of any detectable personality in place of that wink. The plot is straight Amazing Stories boilerplate. Dateline 1957: A “meteoroid” touchdown in the Mojave crash-lands an intergalactic marshal and his prey-a faux-cheap one-eyed purple people-melter a la It Conquered the World. All attention seems to have gone into the period’s surface elements (though the pseudo-Technicolor saturation doesn’t jive with the black-and-white B-picture material). There’s Jody Thompson as a Good Housekeeping covergirl in her halter-neck print dresses, mint finback Chevy rentals, and all the proper tropes herded into place: disbelieving small-town constabulary; a tabloid-addled hick; necking teenagers; and a final, contemplative “We’re not alone” monologue. But the pleasures of genre depend on invention within margins, not just prop department scavenger hunting. It’s hard to see why Alien Trespass seemed necessary with the well of mid-century sci-fi homage having already been memorably visited by-off the top of my head-Matinee, Maniac Mansion, that The Blob remake, Mars Attacks! . . . (the last worthwhile thing Tim Burton touched). All that’s here is diluted nostalgia and Johnny Rockets decor.