Though it isn't even trying to scare you, this is a very nifty black-comic horror movie, one of the rare entries in the genre with some genuine wit and affection. A group of film students put on an all-night schlock-horror-film marathon featuring many of the gimmicks (like Aroma-rama) that sold these sorts of pictures back in the '50s. The theater is haunted by a murderous phantom (Tom Villard) who hides his singed face behind an array of latex-skin masks a device lifted from Darkman, though the special effects here are even more imaginatively authentic than they were in Sam Raimi's film. The phantom, who's the usual embittered romantic, lets out his rage in hilarious, punky wisecracks: Donning his fake skin, he even quotes T.S. Eliot about putting on ''a face to meet the faces that you meet.'' What really makes Popcorn worth seeing, though, are its lovingly detailed parodies of low-budget '50s horror flicks (they include Attack of the Amazing Electrified Man and a giant-bug number called Mosquito), which mimic not only the desperately unconvincing special effects but the inimitable squareness that made those movies such a hoot.