Small talk: Horny alien Garry Shandling and lovelorn Annette Bening, in What Planet Are You From?Photo: Francois Duhamel/Columbia/Tristar

What Planet Are You From? is a bit like a middling Saturday Night Live sketch stretched to feature length. It has a fluky, mild affability and some fine performances, but it wafts into the ozone while you’re watching it. Expectations for this piffle might not be so high if it were the work of a new, young filmmaker with a couple of sitcom episodes to his credit. But because Mike Nichols directed, one expects a bit more something. And since Garry Shandling, who also stars, is a co-screenwriter and producer, the letdown is doubled: Any old segment of The Larry Sanders Show had more invention and larcenous wit.

Shandling plays Harold, an alien from a planet four solar systems away populated entirely by cloned robotic males. His mission is to arrive on Earth and impregnate a woman, played here by Annette Bening, in order to carry out his planet’s ambitions to colonize us from within. The jokiness works at a fairly crude level, and the sentiment, when it begins to seep in, is fairly crude, too. Along with Elaine May, Nichols brought a new, supersmart causticity to revue-sketch comedy. The comedy in What Planet Are You From? doesn’t draw on the tradition he helped create, and it also doesn’t draw on the more surefire commercialism (dolled up as social satire) of The Graduate or The Birdcage, or his Neil Simon stage and screen stewardships. Nichols’s movies are often meticulously crafted to the point of parchedness, and he may have taken a swing at this Wiffle Ball as a way to limber up. I’m not complaining entirely; I’ll take a Wiffle Ball over a medicine ball any day, and, after some of Nichols’s more serioso entries, like Regarding Henry and Wolf, who would wish for more of the same? The problem with What Planet Are You From? isn’t so much that it’s minor but that it’s so cut-rate. Its cheapjack, knocked-off quality is almost a form of effrontery.

The film’s pifflishness wouldn’t be so bad if you didn’t also get the hearts-and-flowers treatment alongside it. Nichols and Shandling are trying to set up Harold, with his emotionless demeanor and lewd, programmatic pickup lines, as an intergalactic example of the way all men behave. It’s a ticklish notion: Males across the cosmos are more in tune with each other than they are with any woman. But then the filmmakers turn Harold’s story into a cosmic immigrant’s quest for humanness, for family feeling, and it gets awfully touchy-feely. Coneheads covered a lot of this same territory. And it was funnier.

It doesn’t help that Garry Shandling seems permanently zonked in the role. What’s funny about Shandling normally is how his zonkiness camouflages the squiggles of hate and cunning that keep breaking through his big-haired Howdy Doody visage. When, as Harold, he goes on about how he doesn’t know what love means and all that jazz, you keep expecting him to snap out of it – for the movie’s sake, if not his own. Playing opposite Shandling, Greg Kinnear, as a lecherous co-worker in a Phoenix bank, steals most of their scenes simply because this crumbum Lothario with an intimate knowledge of the local titty bars is so unregenerately piggy. As intergalactic male exemplars go, Kinnear’s character at least has a pulse, which puts him a beat ahead of Harold.

Annette Bening’s performance is far and away the best thing about What Planet Are You From? It’s so good that you wish it were in another movie. (I like her better here than in American Beauty, where her shrillness kept hitting you over the head.) As an AA graduate with a string of bad love affairs, Bening’s Susan is a fidgety mess in search of redemption. Her early scenes with Harold reveal such a longing for a life change that you actually want her to hook up with the big zero. She has an ineffably charming moment when Harold comes home and she surprises him by singing “High Hopes” while performing a girlish little shimmy. Bening’s full-fledged tenderness in this movie deserves a better foil. If she were playing opposite, say, Steve Martin, an actor who really knows how to communicate the ardency behind the frozen mask, the film might have been out-of-this-world in more ways than one.

A final thought: Why isn’t Mike Nichols acting in the movies? His performance a few years back in The Designated Mourner was one of the most extraordinary extended monologues I’ve ever seen anywhere. His character had a voracious, sorrowful creepiness that seemed to issue entirely unimpeded from the actor’s soul. On the basis of that performance alone, Nichols stands as one of our finest actors. Why deprive us of more of the same? What planet is he from, anyway?

As a pop performer and recording artist, Madonna still bestrides the world like a colossus, but she’s never been a movie star. The brassy sass that makes her a pop-cult diva seems to work against her on film. She’s one of the least sexy of screen presences, because there’s no vulnerability to her, no softness. When she tries to play someone who’s yielding and caring and hurt, as she does in John Schlesinger’s The Next Best Thing, she turns into a mopey blank; the hard sheen of her allure doesn’t lend itself to softer shades. As Abbie, an unlucky-in-love yoga instructor whose gay best friend, Robert (Rupert Everett), has presumably fathered her child, Madonna never gets a chance to show off her vaunted chemistry with her co-star; she’s too busy being winsome and victimized. And victimization has never worked well for her in the movies. (It doesn’t work for Sharon Stone, either, another vamp diva best observed in the predatory mode.)

As a result, Rupert Everett has to carry the movie pretty much on his own, something he seems revved up to do anyway. With My Best Friend’s Wedding and now this, Everett has officially become Hollywood’s Designated Gay Actor; he snaps out the film’s sitcom-ish comedy lines as if he were still appearing in the film version of Oscar Wilde’s An Ideal Husband, and when the film takes a weepy turn as Robert and Abbie battle for custody of the boy he has raised with her, he sparkles with a four-carat anguish. Everett is an entertaining hambone, but too much of a case should not be made for the sexually liberating effects of his screen persona. Camp is camp, whether it’s aboveground or underground, and as for The Next Best Thing, it mostly plays like a none-too-inspired multiple-choice variation on Hollywood’s standard parenthood-and-custody playbook.