The main criticism of AT THE EARTH'S CORE is that it's cheap, the special effects are bad and so on and so forth. Yes, some of the special effects are painfully bad but what a lot of folks overlook about it is that it's actually quite fun, which is very important in my book.
In comparison, just look at the latest STAR WARS films: they have the latest, greatest special effects created by the latest technological advances which are capable in creating stunning visual effects as far reaching as the human imagination can imagine and yet, with all the razzle dazzle, those films were as exciting as a funeral. As Yoda would say, Fun they're not! In other words, who cares if the FX aren't the greatest when the spirit of the film is fast-paced, humorous and clearly set on the side of action. I love everything about AT THE EARTH'S CORE: the contrast between stodgy Victorian England VS the wild other-worldly, colorful setting of Pellucidar, the cast of characters, the concept of a lost underground world, the telepathic Pterodactyls, the human slaves rebelling, Jubal the ugly one (lol!), the inspired teaming of Peter Cushing (who's great!) and Doug McClure, the excellent music (it's really good), cinematography by the amazing Alan Hume and last but not least, Caroline Munro. She's effing sexy in this movie. One of the sexiest B-movie babes ever captured on screen.
Seriously, anyone who doesn't like this movie doesn't know what fun is. Gimme AT THE EARTH'S CORE over any turgid STAR WARS prequels any time! At least it has Caroline Munro, which no CGI fx can ever recreate.