Alice Stoehr’s review published on Letterboxd :
It'd been years since I last saw this, and although (of course) I remembered the story's loose outline, many of the smaller details startled me. A few thoughts on that:
• It looks and sounds exactly like top-shelf film noir! The sequences where Miles and Becky flee from "the police" are especially reminiscent of movies like Detour or Dark Passage, and even James Wong Howe could hardly have improved on all the headlights and flashlights slicing through the night. The film's photography progressively hems in its remaining human characters, penning them first in Miles' office, then beneath the slats of a mineshaft floor. Invasion is among the leanest, most suffocating nightmares in all of cinema.
• What if you didn't know this was a sci-fi movie? What if you ran across it on TV and decided to keep watching? The first bit of real evidence (the incomplete body) doesn't show up until 20 minutes in, and Miles doesn't discover the seed pods until 20 minutes after that, by which time the film's half over. Prior to that, though, the film froths with insinuations of the uncanny. Its red herring mystery, in which a small California town experiences an epidemic of Capgras delusion, both sets up the real conspiracy and is intensely upsetting in its own right.
• The special effects in this are so unsettling. The blankness of that body's face and fingers play like the punchline to a sick joke until its true implications start unfurling. And I'm still shuddering from the foam spewed out by those seed pods in the greenhouse. The pods are grotesquely yonic, and as such call to my mind the monster from The Quatermass Xperiment (1955). Much of '50s sci-fi may have been visually flat, but effects like these gave filmmakers opportunities for in-genre experimentation that sometimes verged on the psychosexual or the avant-garde.
• Is this the most consistently well-told story in film history? Granted, I haven't seen 2007's little-loved The Invasion, but the Siegel-Kaufman-Ferrara trifecta is formidable, with each director pursuing a very different yet equally terrifying angle through the material. The closest competitor I can think of is All That Heaven Allows and its progeny, wherein Sirk-Fassbinder-Haynes do for the past half-century of melodrama what the Invasion crowd did for horror.