It's a spoof to be certain, but of what?  War films?  The ails of the movie industry?  Or both?

Leave it to Ben Stiller to take a novel approach to a late-summer comedy. Tropic Thunder is a movie about the making of a movie drowning in budget crises and bogged down by prima donna actors. It pokes fun at the rampant sequelitis for which action flicks are known and it relentlessly jabs at the quirks of the movie industry as a whole. It is spoof taken to an entirely new level. Tropic is also decked out with an all-star cast and cameos; to name a few, Mickey Rooney, Tobey Maguire, John Voight, Jennifer Love Hewitt, Alicia Silverstone, and even Tyra Banks make an appearance—and those are just some of the cameos.

But beyond the star-studded surface lies a gritty comedy that isn’t afraid to offend anyone and everyone, whether by means explicit or implicit. You know the rules are different with Tropic when the opening previews are sabotaged by a threesome of (hilarious) back-to-back spoof trailers introducing three of the film’s characters. Afterward, we’re taken to the set of the sixth Scorcher film, starring the venerable Tugg Speedman (Ben Stiller) as the Rambo-like star of the wildly derivative and outrageously unrealistic cash cow of a flick. Problem is, the movie isn’t turning out to be the cash cow it was originally envisioned. That’s all thanks to the cast of the movie, who simply can’t seem to stop whining about how it’s being made.

Along with Tugg Speedman, the cast also includes Jeff Portnoy (Jack Black), a comedy-turned-action drug addict of an actor who made his name doing The Nutty Professor -esque film “The Fats”; Kirk Lazarus (Robert Downey Jr.), an Australian method actor who takes his black-faced role (yes, you read that right) in the movie so seriously that he underwent pigmentation surgery; Alpa Chino (Brandon T. Jackson), a rap star who has begun to Jay-Z his way into film; and Kevin Sandusky (Jay Baruchel), a young geek of a kid who hopes the film with score him some attention from the high school ladies. But that’s never going to happen at the rate things are going.

At the heart of the problem is Tugg himself, who repeatedly interrupts a key scene where he and his fellow soldier, Sgt. Osiris—played by Australian actor Kirk Lazarus—are meant to be sharing a touching exchange of tears and dying words. The interruptions result in some extremely expensive props being wasted, and the heat from the press is beginning to mount. Flustered and desperate, the film’s director, Damien Cockburn (Steve Coogan) decides, per the advice of war veteran and film writer Four Leaf Tayback (Nick Nolte), to simply drop the actors in the actual Vietnamese jungle. Having rigged the jungle with hidden cameras, he plans to capture the scenes by forcing the circumstances upon the uncooperative actors. However, predictably, things go horribly wrong.

Without spoiling too much, the ensuing sequence of events is just what you might have deduced from the previews—the group is left to fend for themselves amongst hoards of Vietnamese savages all while a clueless Tugg Speedman maintains his stance that the whole thing is all just part of the director’s wily plan to elicit the kind of acting he’s in need of.

But that’s really not the appeal of the movie anyway. The plot is amusing, yes; but more than anything, Tropic is a rousing collection of skits that just so happens to feature well-known actors playing some pretty adventurous roles. Case in point, we get to see Tom Cruise play perhaps his funniest role of his entire career as Les Grossman, the shamelessly selfish and offensive movie bigwig who repeatedly flaunts his impropriety in a variety of eloquently profane ways, and Matthew McConaughey as Speedman’s agent, Rick Peck, who loves his Wii almost as much as he does Speedman and his TiVo—almost. And who could forget Robert Downey Jr.’s performance as an Australian playing a black man? He does a remarkably good job, and Tropic even takes the liberty of poking fun at Kirk’s stereotypes of the role (Alpa Chino in particular is not impressed).