The film suffers from an awkward & heavily expositional script as well as some dreadful supporting performances during the first act. However, the intelligence & intrigue of Kneale's ideas are always fascinating. If the film succeeds, & it does (to an extent), it's down to the incredible atmosphere that is generated throughout; the prolonged sense of creeping menace & a visceral push towards apocalyptic annihilation.
Cinematic adaptation of a TV series that BBC wiped from existence making this is the best existing presentation of one of the first serious science fiction series made in England. It is a good movie whose plot is of such high quality it was reused for "Lifeforce" and other movies later. Professor Quatermass is like a scientist detective and the plot also unfolds like a crime story which I like". Beautiful production.
An excellent expansion of Kneale's earlier BBC serial with a splendid sense of place and the best of a generally satisfying trilogy (this is certainly the better cast of the lot). There's a solid certainty to the pseudo-science and, later, demonic-rising which frighteningly rounds off the relative seriousness of the endeavour.