Fox Searchlight Pictures
Martin Freeman and Jessica Stevenson in "Confetti," a British mockumentary.
CONFETTI — ** 1/2 — Martin Freeman, Jessica Stevenson, Stephen Mangan; rated R (nudity, language, mild violence).

It's not stupid. The performers give it their all (in at least two cases, their altogether, too). It doesn't get too cutesy like so many British comedies. And heaven knows, the subject is worthy of satire.

So I'm not really sure why the improvised British mockumentary "Confetti" hardly ever made me laugh. This is a case where it really could be me; throughout the screening, my brain was telling me that someone else may quite legitimately bust a gut at this thing.

What it is about is a competition to stage the most original wedding in Britain. "Not everyone wants their wedding ruined by a gimmick ... but some do," reckons the publisher of Confetti magazine, a slick publication devoted to all things nuptial. He sponsors a contest in which three couples vie for a million-dollar dream house. And as you can probably tell from the quoted line, this movie has parallels to Christopher Guest's films ("Waiting for Guffman," "Best in Show") and whiffs of "The Office" (both versions) all over it.

But "Confetti" comes off more like a reality TV show, in which the participants just don't express their obsessive cluelessness as exquisitely as sharp writers can through trained actors.

Make no mistake: "Confetti's" ensemble cast is all pro. But director Debbie Isitt left them to their own improvisational devices to a greater extent than even Guest does his well-oiled rep group. There's no story credit on this film, let alone one for even a rudimentary scenario. The actors did an impressive job of filling in and fleshing out. But you can sense the strain in some scenes, while others don't seem developed enough.

And that's probably why I didn't chuckle much. But if any of the following ideas tickle your funnybone, by all means go and have a ball.

The three finalists are:

• Matt ("Love Actually" and English "Office's" Martin Freeman) and Sam (Jessica Stevenson), who want a Broadway musical-themed ceremony but can't sing or dance.

• Josef (Stephen Mangan) and Isabelle (Meredith MacNeill), super-competitive and, by extension, obnoxious, tennis players.

• And the naturists Michael and Joanna (Robert Webb and Olivia Colman, both of whom hail from television's appropriately titled "Peep Show"). They want a nude wedding, of course, which is the last thing that Confetti's editor wants.

There is also a gay pair of wedding planners, Archibald (Vincent Franklin) and Gregory (Jason Watkins), whose every suggestion is violently rejected by each couple.

Potential disaster threatens every step to the three-way happy day. I don't want to spoil any surprises, but let's just say that "Confetti's" big climax is satisfyingly over the top.

"Confetti" is rated R for nudity, language, mild violence. Running time: 94 minutes.