These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Narm Charm: The whole point of the movie! Especially the ridiculous noises the spiders make! They roar, they hiss, and when they're hurt they act like cartoons! When set on fire they squeal, when squished they go "bleah", and you might even hear a "whee" or two!
Nightmare Retardant: Granted, it's by no means a straight horror flick to start with, but the goofy noises the spiders keep making can easily defuse the terror for non-arachnophobes.
The movie's first death is caused by a (regular sized) pinktoe tarantula, granted it's already supposed to be a giant mutant, but they used a regular Avicularia Avicularia as the killer spider. Pinktoes are generally known by hobbyists as one of the gentlest, most docile, most timid of tarantula species. It's the equivalent of making a movie about killer wolves and have the first death caused by a basset hound.