Critical
The Monthly Film Bulletin wrote: "Quite the most alarming thing about this horror ffm Is Joan Crawford's performance, beside which impaled skulls and Diana Dors being sawn in two pale into insignificance. First glimpsed as a vampiric apparition in black tights and scarlet tailcoat, she soon melts into something more voluminous to gloat over her youthful lover, meanwhile scorching him with basilisk glares of possessiveness and cracking her lines all round the circus like a metaphorical whip. Her efforts, unfortunately, are all to little avail, as the script is rudimentary to say the least ... The denouement – after a rather good sequence of Ty Hardin's last high-wire act and demise – must be one of the most perfunctory on record, with climactic murder, confession and retribution all whizzing by in about thirty seconds flat." [13]
Variety wrote: "Story is full of holes, but it makes no difference. All the elements of the thrill picture are present. Promotion will bring them in. Berserk doesn't have the continuous attention-holding gimmick of, say, Invisible Man or House of Wax, but it fills the gap between its four sensational murders with a colorful array of circus acts and loosely constructed story line. For Joan Crawford, owner and ringmaster (in leotard, red jacket, and top hat) of a circus plagued with brutal killings, it's more of Whatever Happened to Baby Jane? or " Straitjacket effort. All good showmanship." [14]
Howard Thompson wrote a mostly negative review in The New York Times , comparing it unfavorably to Circus of Horrors , but also commented, "It's also hard to make a hopeless movie with a circus background and sawdust aroma. This is the one solid thing the picture has going for it – the intriguing workaday routine of circus folk and some good, spangly ring acts, all handsomely conveyed in excellent color photography. And under the reasonable direction of Jim O'Connolly, the film does project a kind of defiant suspense that dares you not to sit there, see who gets it next and, finally, why." Thompson stated that Crawford "... is professional as usual and certainly the shapeliest ringmaster ever to handle a ring microphone." [15]
Lawrence Quirk wrote in Hollywood Screen Parade that "[Crawford] is all over the picture, radiant, forceful, authoritative, a genuine movie star whose appeal never diminishes." [16]
In The Radio Times Guide to Films Tony Sloman gave the film 2/5 stars, writing: "Here, in the twilight of her career, Joan Crawford stars in a tale about murderous goings-on in a circus, which is at least marginally better than her caveman fiasco Trog . It's a shame to watch an actress of Crawford's stature gawking at such explicit sadism, for many that is this tawdry flick's main appeal. Cheap and nasty." [17]
