Is Joaquin Phoniex a put-on artist? Manohla Dargis reviews “I’m Still Here”:

For a twitchy, perversely funny stretch, he mumbled and fidgeted, softly, often monosyllabically, responding as Mr. Letterman’s formulaic jive grew testy. “What can you tell us about your days with the Unabomber?” Mr. Letterman asked at one point. Mr. Phoenix looked down while the audience roared at a joke few seemed to grasp.

More than a year later the joke continues, sputters, occasionally hits its target and finally wears out its welcome in “I’m Still Here,” a deadpan satire or a deeply sincere folly (my money is on the first option) about Mr. Phoenix’s recent roles as an acting dropout and would-be hip-hop artist. Directed by Casey Affleck (who’s married to Mr. Phoenix’s sister Summer), the movie, which is being unpersuasively sold as a documentary, is a gloss on the mutually parasitic worlds of celebritydom and the entertainment media. Those are worlds Mr. Phoenix knows well, having fed the beast since his breakout role as Nicole Kidman’s poignantly thickheaded lover in “To Die For,” Gus Van Sant’s 1995 comedy about the tragedy of fame.

“I’m Still Here” isn’t as merciless as “To Die For,” which was etched in acid by the screenwriter Buck Henry. Mr. Affleck and Mr. Phoenix have been involved in the movie business long enough to be disgusted (or maybe just irked) by it, but they don’t appear to have surrendered to cynicism. Whatever else their movie is, and whatever their actual intentions, “I’m Still Here” does take on, at times forcefully and effectively, the pathological fallout of the Entertainment Industrial Complex. Much of the movie involves Mr. Phoenix’s having, or more likely pantomiming, a meltdown, for which he puts on a really good show. (He snorts white powder, hires a hooker, abuses his assistants.) But the programmatic nature of his antics strongly suggests that he is self-consciously playing a role in a narrative, one that isn’t simply about him.