My word, what lost potential! Even just the basic set-up. Put it in the hands of a far superior writer who could make those other couples' matter, who could make the FBI plot relevant, change the monster to something more interesting (reptilian superbeasts! [but that's another unfunny in-joke]), reduce the obviousness of the Living Dead basis, double the page length (or even double it and then a half again) and you could conceivably have had yourself a horror classic. As someone who occasionally turns my hand towards writing words instead of notes, this certainly sounds - from such promising material -, as you say, "handled hamfistedly."