Alarmed (but not altogether surprised) by the cat, very spooked by the spider (but much better at coping with them these days), but found the ending unforgettably disturbing. I first saw it as part of genuine all night science-fiction marathon, where it was not as outright scary as the original King Kong (big screen - those teeth!) but existentially worrying as much good science fiction can be.
Re- release it Hollywood - but hands off ever remaking it! Can't we have some sort of preservation order on cinema classics that are just fine as they are?