The Informant! is "a return to form" for director Steven Soderbergh, said David Denby in The New Yorker, and the film's star, Matt Damon, "is on fire." Based on a book of the same name about "corporate whistle-blower" Mark Whitacre (played by Damon), The Informant! (watch the trailer) is "a vertiginous experience that grows increasingly hilarious" as Whitacre takes foolish risks to expose price-fixing at Archer Daniels Midland.
"If you're on Soderbergh's wavelength," said Marshall Fine in Hollywood & Fine, "you'll laugh yourself silly at the chutzpah of The Informant!" But the entire movie is "built around a Damon performance that captures the manic high of a man who needs a lithium drip," and it will "either amuse or infuriate you, depending on your tolerance for the ramblings of someone suffering from attention-deficit disorder spiked with a case of bipolarity."
The Informant! could have been a compelling exploration of "corporate misbehavior," said David Edelstein in New York magazine. Instead, Soderburgh made it merely a Halloween freak show featuring a "fatted Matt Damon" with a pompadour wig and thick glasses. Exploring the duality of Whitacre's psyche is simply not that interesting—"he's just a nut."