Promiscuous teens being hunted by a stony-faced killer - sounds like a fairly hackneyed horror trope, doesn't it?
What makes It Follows stand out is the tiny wrinkle in the formula, which allows the film to explore new territory: what if you are being stalked by a stranger only you can see?
Here, a malevolent shape-shifting presence inhabits the bodies of random individuals, and relentlessly pursues its victims on foot. Like the classic zombies of old, you can easily escape, but it is relentless. However far you run, it will get you in the end.
Writer/director David Robert Mitchell's film effectively evokes feelings of paranoia and dread, and leaves you involuntarily scanning your surroundings for strangers making a beeline toward you.