I read a review today that criticized it for one thing I think ISN'T bad, and that's the fact that it's in color (in spite of being a " ' 50s sci-fi" parody). Not only isn't that a bad thing to me, but I've always had a pet peeve about using black and white to underline something (not always nostalgia, but very often). I just think that it's helpful (let alone necessary) a lot less frequently than other people seem to. My big exception to that (when it comes to horror parodies) is Young Frankenstein, but I do think it really gets overdone.
One of the films of this kind that DID work, that hasn't been mentioned on this thread, is Psycho Beach Party. I know people usually say this about parodies, but that one was pretty clearly made with a lot of "affection," not just for the horror movies but for the BEACH MOVIES.