A good test you can give yourself to determine whether or not you would like Tim & Eric's Billion Dollar Movie is:
1: Have you seen Tim & Eric before on TV or the internet?
2: Did you like what you saw?
If you answered yes to both of those questions, you just might enjoy their movie. These guys are the definition of the words "Not for Everyone". Over the years, Tim Heidecker and Eric Wareheim have made a career of their shorts, that often use amateur techniques that are indistinguishable from a 1980's VHS infomercial that you might find in a bin at a Salvation Army. Their comedy is surreal, obnoxious, subversive, and often will take a turn for the nightmarish. Their unique voice has also earned them the respect of pretty much everyone else who matters in the comedy world, if not the world at large.
Now Tim & Eric have taken their first step into the movie world, and it's every bit as strange and culty as you would expect. Tim & Eric's Billion Dollar Movie, is the story of Tim & Eric, playing themselves, who somehow got a billion dollars from Hollywood studios to make a movie. The movie that resulted, "Diamond Joe", starring a Johnny Depp impersonator in a suit made of diamonds, cost so much money that they were only able to shoot three minutes of it. They are held responsible by the studio heads, and must find a way to pay back the billion dollars. As luck would have it, they see a commercial where a man offers a billion dollars to anyone who can fix up his shopping mall.
Tim & Eric then form a PR firm called "DOBIS" (the origins of that name was one of my favorite bits), and set out to bring business back to a dilapidated shopping mall with used toilet paper stores and a sword shop whose owner doesn't actually want any business. The plot really makes little sense. It's just there to loosely tie together a bunch of weird characters and bizarre jokes.
So does it work? As someone who enjoys Tim & Eric, though I haven't watched a lot of them, I think a lot of it does. It's not perfect, but a lot of the jokes got me. For example, I really liked when they first meet the owner of the mall (Will Ferrell) and before they talk, they watch Top Gun together. When it's over, they watch it again. I also liked the showdown with the movie studio heads at the end. As I said, I laughed a bunch, though I didn't care for the scatological stuff, as bizarre as some of it was.
Tim & Eric are two comedians who really don't seem to care if they're making everybody laugh, or just themselves. I respect that attitude a lot. It's how they got their cult status in the first place. In their movie, they surround themselves with bigger stars (and frequent collaborators) who are similarly fearless and unconcerned with reaching everybody or just the few people like them. Supporting roles are filled by kindred spirits such as Will Ferrell, John C. Reilly, Zach Galifianakis, and Will Forte, all fully willing to give themselves over to Tim & Eric's weird vision.
I think you should only watch this if you're a T&E fan already. They have 5 seasons worth of insane, surreal sketches, most of them posted on Youtube. You should check some out if you haven't, these guys actually work better in short bursts than they do at feature length. If you've watched their Adult Swim show and approve, you might find some enjoyment in the Billion Dollar Movie, though I can't imagine someone unaware of these guys making it through 90 minutes of their antics.