Dug this out of the amazon reader reviews because I always liked it; I think "a customer" was changed from something funnier:
monkeys, maniacs, mutants, and creepy crawlies by the ton, March 8, 1999
By A Customer
This review is from: Phenomena (1984) (Ws Rmst) (VHS Tape)
What more could you want from a horror movie? A pretty schoolgirl who commands armies of insects, a knife wielding serial killer, a deformed boy kept chained to a wall in the attic, a vengeful helper monkey with a razor blade, Donald Pleasance, delirious camerawork, blindingly gorgeous cinematography, pulsating music, characters who behave strangely for no particular reason, lots of pockets of glowing blue light (see where X-Files got some of their aesthetic ideas), surreally graphic violence, beautiful scenery, it's all right here. Sure, it's not Dario Argento's best work, but it's his most eccentric. Besides, why not watch a real horror film instead of Scream?
I've been using "characters who behave strangely for no reason" to describe Argento's films since I first read this.