This movie is based on a semi-autobiographical Philip K. Dick novel. The cool thing here is rotoscoping, which takes live-action footage and transforms it into something that looks more like animation. In this movie, it's useful for portraying drug-induced hallucinations, a suit that disguises the indentity of its wearer, and Winona Ryder's breasts.
The main problem, though, is that the movie doesn't have much to do. The premise is: undercover cop gets his brain addled by "Substance D", a drug that plays havoc with the normal functioning between the two hemispheres of the brain. There's a bunch of stuff about paranoia, betrayal, and ubiquitous high-tech surveillance. But all this is padded out with nightmarish drug-fueled wacky hijinks and elliptical dialog, which gets old fast. (Even Robert Downey Jr.'s motormouth character seems initially witty, but it's a trick that goes on too long.)
I don't own the book, but the film duplicates part of Dick's afterword:
This has been a story about people who were punished entirely too much for what they did.… followed by an impressively long list of deceased and permanenly-damaged people. Then:
In memoriam. These were comrades whom I had; there are no better. They remain in my mind, and the enemy will never be forgiven. The "enemy" was their mistake in playing. Let them play again, in some other way, and let them be happy.According to Wikipedia, the afterword also contains the statement
[D]rug misuse is not a disease, it is a decision, like the decision to move out in front of a moving car.… but that didn't make it into the movie. Wonder why not?
The DVD includes interviews with the participants, and also some old footage of Philip K. Dick discussing his (admitted) paranoia and his persecution by the US government; how much of the latter is an imaginary result of the former is anyone's guess.
Winona Ryder is also interviewed, and she makes the obligatory point that, gee, government snooping into our lives is really bad. She didn't say anything about security cameras at Saks.