A would-be romantic comedy from New Zealand about two purportedly lovable eccentrics who seem more like mental defectives, “Eagle Vs. Shark” wants to be charmingly off-kilter but comes across as insufferably grating. Ultimately this is a struggle one wants neither party to win.

Lily (Loren Horsley) is a droopy-faced worker at a fast-food joint who’s unaccountably enamoured of a scowling, bearded fellow who occasionally pops in for burgers—Jarrod (Jemaine Clement), an adolescent-minded clerk at a video game store. When she comes uninvited to his video-game costume party dressed as a shark (he’s the eagle) and proves herself a wiz—though a neophyte—at the games, they immediately hit it off and have sex (a first for both, one suspects). They seem destined to be together.

Unfortunately, it appears that fate will tear them apart all too soon, since Jarrod is about to leave for his out-of-the-way hometown to confront the bully who tormented him in school. But Lily, not to be deterred, goes with him, leading to a strange and not very funny encounter with his equally oddball family—a wheelchair-bound dad still mourning the death of his older son, whom he much preferred to Jarrod; a sister and brother-in-law who appear to be selling everything from track suits to cosmetics; and a couple of children, one Jarrod’s guitar-playing younger brother (I think), and another his niece, who dances with the brother’s “band.” (Of course, Lily’s relatives aren’t much better: she has a doofus brother whose main contribution to the world is a series of horrendously bad imitations of famous actors.)

Jarrod, meanwhile, is preoccupied with his training for the big confrontation (cue some lame “Rocky”-style slapstick with martial arts overtones), and ignores poor Lily, who becomes more and more dejected. Their relationship seems to be unraveling, but despite the fact that the fight for which Jarrod’s been preparing doesn’t go as expected (his opponent turns out to be disabled), they do eventually wind up together, though they’re just as sad and pathetic as when the movie started.

The humor in “Eagle Vs. Shark” is supposed to be deadpan, but only the first syllable applies. This is a drearily slow and amateurish slacker comedy, a thoroughly condescending piece that will be funny only to those who enjoy laughing at characters rather than with them. All the so-called people in it are losers of one sort or another, more pitiable than amusing, and the actors don’t have the chops to make them agreeable company. In particular Horsley, who looks a bit like Molly Shannon with a perpetually downturned mouth, and Clement, who seems typecast as a surly ubernerd, seem way too old for this sort of stuff. They do not come across as a couple made in heaven, on or off screen.

There’s also a bit of stop-motion animation periodically dropped into the picture, most of it involving a half-eaten, rotten apple. I haven’t the slightest idea what comment it’s supposed to be making, but suffice it to say that the apple isn’t the only thing rotten here.