A Scanner Darkly was screened at the South by Southwest Festivals in Austin, Texas and rottentomatoes has a review up from it:
Tim Ryan writes: "Richard Linklater's "A Scanner Darkly" was screened unannounced at South by Southwest, and though the audience was told the film is still being tweaked for release in the summer, the movie is pretty compelling stuff.
In the not-too-distant future, Robert Arctor (Keanu Reeves) is working undercover to bust a purported drug ring; the drug in question is substance D, a highly addictive substance that scrambles the brains of its users. Arctor is so far undercover, in fact, that he begins using the drug, and becomes more paranoid as the reasons for his mission become clearer. The film was adapted from a novel by Philip K. Dick, and it contains many of the themes of his other works: fear of Big Brother, a totalitarian future, and technologies that make life more restrictive.
As with "Waking Life," the filmmakers shot the actors on video and then animated their likenesses in a way that creates a dreamlike hyper-reality. The technique is right for the material; the additional veneer heightens the features of such recognizable faces as Reeves, Winona Ryder, Robert Downey Jr., and Woody Harrelson, and it contributes to the film's surreal air. If it's not always clear what's happening, and if "A Scanner Darkly" doesn't match "Waking Life"'s wonderfully fluid meditation on the nature of existence, it's still a remarkable visual experience and an involving drama -- albeit one that takes a while to wrap your head around.