That's the great thing about Tremors - the expectations are not high. It wears its B-movie credentials on its sleeve. The worms are... unconvincing but good enough to not draw you out of the film (like the Rodents of Unusual Size in Princess Bride). It's just plausible enough that you willingly suspend disbelief - "sure, there could be giant killer worms in this weird and forgotten corner of the California/Nevada border... I guess." Tremors benefits greatly from low expectations. It doesn't have to succeed much in order to succeed. By way of comparison, Waterworld was originally intended to cost about as much as Tremors. It was supposed to be a movie like Steel Dawn: But it got burdened with a budget the size of Titanic and nobody wants to watch that except for the schadenfreude. M Night Shamalyan described Lady in the Water as "A $60m art film" without appreciating that nobody makes $60m art films. The guys behind Tremors took that one to heart.