It's easy to forget the clever, absurdist Ben Stiller behind The Ben Stiller Show, especially since the mugging dumbshow Ben Stiller of Meet The Parents is generally much more visible. Stiller's performance is easily the weakest element of Tropic Thunder: Like his Zoolander character, he only has a handful of exaggerated expressions, and he cycles through them on cue. But it's easy to forgive him, given how thoroughly enjoyable Tropic Thunder is on virtually every other count. Where Stiller the actor seems outmatched by the more expressive talents on display, Stiller the co-writer and director contributes a lively, layered comedy packed with cheap but hilarious goofs on Hollywood, from fake trailers for horrible (yet strangely familiar) movies to roman à clef parodies of Hollywood personalities to actors and celebrities outright mocking themselves.
The story centers on a big Hollywood war movie on its way down the tubes. It's "a month behind schedule five days into shooting," thanks to its ego-driven stars—a failing former action hero (Stiller), a heroin-addicted, sloppy comic branching out into drama (Jack Black), and a multi-Oscar-winning Method actor who says he doesn't drop character until the DVD commentary (Robert Downey Jr.). When they blow a catastrophically expensive take (in a gag borrowed from Peter Sellers' The Party), harried director Steve Coogan and the crazed vet whose Vietnam memoir forms the basis for the film (Nick Nolte) conspire to throw the stars into the jungles of Southeast Asia and let them fend for themselves, with the cameras rolling to capture their improv adventure. Naturally, that plan quickly falls apart. Meanwhile, on the home front, Stiller's agent (Matthew McConaughey) misunderstands the situation, while the picture's snarling, villainous producer (an eerily balding, hairy, muscled Tom Cruise) sets him straight.
With so many big names and outsized characters at hand, Tropic Thunder easily could have become overstuffed or overblown, and its broad, lowbrow humor rarely reaches beyond "Bad films and bad actors are funny!" Stiller and his co-writers fix both problems by cranking up the speed, zipping fleetly from one gag to the next so fast that there's no time to focus on flaws. The film only pauses when lingering over Cruise's foul-mouthed studio tyrant, for two good reasons: The way he throws himself into his grotesquely cartoony character, deliberately playing against type, is a total hoot, and it typifies the way everyone in the film goes for the most outrageous and infectiously laughable take on the material. Maybe Stiller just seems stilted because he's the only one here who isn't playing to the rafters.