Mario Bava was remarkably ahead of his time. Around seven years earlier, he had single handedly invented the Giallo thriller with "The Girl Who Knew Too Much" and the seminal "Blood and Black Lace". By 1970, the Giallo trend really began to take off with Dario Argento's initiation into the legendary subgenre with "The Bird With the Crystal Plumage". Does Bava continue to ride on the coattails of the genre when its achieving mass popularity? Hardly. Instead, he crafted this horror film filled to the brim with carnage and grisly murders. The brutality in "Twitch of the Death Nerve" goes far beyond what was being shown in the Giallo subgenre at the time.
Additionally, Bava introduced many interesting and unique plot devices with this film. There's a group of teenagers who stumble upon an abandoned cabin on a lake, have a lot of sex, and are systematically killed off one by one. Sound a bit familiar? Bava was laying the groundwork for the slasher film, a full nine years before the release of "Friday the 13th", which is often acknowledged as the movie that spearheaded the trend of slash-and-dice flicks all over the world and pretty much changed horror cinema for better or worse.
What elevates this above your normal slasher flick is Bava's direction. It's exquisite as usual. No other genre filmmaker showed such masterful technique and ability to create atmosphere. The murders themselves are shocking, yet Bava provides a bizarre sense of poetry to them. Sure, the film doesn't have much in the way of a plot and the acting is generally weak, but its still a shocking and beautifully made experience. A must-see for any horror fan. (8/10)