“Park” is the kind of ensemble comedy that was a nagging staple at the Sundance Film Festival in the late 1990s but has all but disappeared in the early 21st century. The film, which opens today, is by turns quirky, cute, and rude, with interconnected characters played by has-beens and never-weres who don’t quite make the cut for VH1’s “The Surreal Life.” Set in a barren recreational area in the Baldwin Hills section of Los Angeles, it revolves around the lunchtime escapades of some eccentric types.

Dennis (William Baldwin), an attorney fixated on enormous SUVs, is at the park to rendezvous with Krysta (Izabella Miko), a Eurotrashy soubrette who slinks into a French maid costume for the occasion. Nearby, Dennis’s wife Peggy (Ricki Lake) and her best friend Claire (Cheri Oteri) stake out the adulterous pair for an ambush. Meanwhile, April (Dagney Kerr), a suicidal washout with a jammed gun and a box of blanks, stumbles upon Krysta’s jilted admirer/co-worker Ian (David Fenner) and hits him up for some help. And Nathan (Trent Ford) and Babar (Maulik Pancholy) confess their warped nudism to skeptical colleagues Sheryl (Melanie Lynskey) and Meredith (Anne Dudek) in the company van.

The premise sounds like a contrived assignment in a screenwriting class that requires students to observe and describe random strangers at a public place. Writer-director Kurt Voelker seems to be fighting the ennui that stems from shooting his film in a lousy L.A. park, and his plot soon drifts into a writing exercise in free association. Even though the film never breaks the confines of the park or ventures fully into meta-Charlie Kaufman land, there are some amusingly absurdist moments. The most memorable is a montage of Peggy and Claire going gonzo with hammers on Dennis’s prized SUV in slow motion, set to a Burt Bacharachesque ditty. The deliberate irony helps the viewer, temporarily anyway, get past the general implausibility of the plots.

Oddly enough, Mr. Voelker is doing fine until he finally falls prey to screenwriting convention. The film’s spontaneity and zaniness are mostly enjoyable, but it fails in its attempt to tie up all the loose ends. Every character undergoes a transformation, but the resolutions are arbitrary and disingenuous. This is when it becomes painfully obvious that Mr. Voelker hasn’t developed the screenplay enough for viewers to care.