District 9” is one of the most frustrating types of film-going experiences.

Here’s a movie that begins with plenty of promise, only to completely fall apart in the second half. The result is a movie that flirts with brilliance, but ultimately fails to deliver.

“District 9” begins like a documentary, with interviews telling the story of an alien ship arriving in Johannesburg, South Africa and hovering above the city. Eventually, the ship is forced open and a large group of sickly aliens are discovered. These aliens are rounded up and forced to live in slum-like conditions.

These early moments of the film are extremely fascinating, diving into some interesting social situations.

Unfortunately, director Neill Blomkamp, who also co-wrote the screenplay with Terri Tatchell, can’t sustain that momentum, largely due to a plot shift that centers around a government agent (Sharlto Copley) who is exposed to a dark liquid that causes his DNA to combine with the alien DNA. When the film shifts to this story line, it collapses, becoming nothing more than a cross of “The Fly” and pretty much any other cookie cutter sci-fi action film.

I’ll admit the action sequences would have been easier to take if the cast was at least interesting, but that isn’t the case in “District 9.” Copley is never a believable protagonist, and his transformation isn’t very believable. About the only interesting cast members are the CGI aliens.

Perhaps if the focus remained on the aliens, then “District 9” would have succeeded. Instead, we get a film with a lot of empty promises that ultimately left me unsatisfied.

DVD dandy of the week

This week’s dandy is “Adventureland” (A-), writer/director Greg Mottola’s smart, funny and tender spring release that will hopefully find an audience on home video.

Jesse Eisenberg stars as James, a recent college graduate who is about to embark on a summer trip to Europe before heading to Columbia for graduate school.

His plans are altered when he learns his father has taken a pay cut and can’t afford James’ vacation and education.

James is forced to get a job working at a local amusement park, where he meets an eclectic mix of characters. Before long, James becomes involved with Emily (Kristen Stewart), a girl dealing with her own issues, including an affair with the married park handyman and aspiring musician, Mike (Ryan Reynolds).

The ads for “Adventureland” play up Mottola’s previous film “Superbad,” suggesting another raunchy teenage comedy, but this film is much more. Sure, there are some funny moments, plenty coming from “Saturday Night Live” alums Bill Hader and Kristen Wiig as the park’s owners, but the film makes the most of its 1987 setting, creating a nostalgic feel on par with films like “Dazed and Confused” and “Almost Famous.”

Hader and Wiig are just a small part of a large cast who all give some memorable work. There are some small touches like Matt Bush (as a guy who constantly torments James) and Margarita Levieva (as the girl object of everyone’s desire who is interested in James) that I really appreciated, but for the most part “Adventureland” works thanks to Eisenberg and Stewart.

Their relationship is tender and quite believable, with an authenticity that sent me back to my high school days in the late ’80s.

People my age should be able to identify with “Adventureland,” but I think this is a film that younger audiences can also relate to.

“Adventureland” is rated R for language, drug use and sexual references and will be available on DVD Tuesday.

— Between prepping for his upcoming fantasy football draft, sportswriter/movie reviewer Micheal Compton plans another big weekend of movies – including Quentin Tarantino’s “Inglourious Basterds.” To get his instant thoughts on anything he decides to see, you can follow him on Twitter at twitter.com/mcompton428. He’s also willing to take your e-mails at mcompton@bgdailynews.com.