NOW IT'S COOL to be middle-aged. The same generation that 15-odd years ago in its flaming youth stole the stage is now dragging culture-consumers of all ages and sensibilities through its mid-life crisis. The children of Marx and Coca-Cola, as Godafd described them in his wonderful 1966 film Masculin-Feminin, are now the adults of EST and Perrier. And their movies--An Unmarried Woman, The Goodbye Girl, Kramer Versus Kramer, and now Shoot the Moon--are self-centered and, mostly, boring. Television is now catching on, with ABC offering a TV-movie that cashes in on both the trend toward family crisis dramas and space adventures with the ungainly title Divorce Wars. The books on pop self-analysis which have bloated the "psychology" section of bookstores are the attempt of this generation to try and adjust rock-and-roll ethics to "parenting" and the rest of adulthood. It doesn't work. The two forty-bound protagonists of this latest addition to the tiresome genre keep talking about "learning to grow up." We seem to have no choice but to watch the maturing of our elders, the best-documented and most self-conscious generation to date, for a good while longer. There are more of them than of any other age group, and they will dominate American culture until they die.

The seventies and early eighties have been a lousy time to be young. They have brought Passages, the New Divorced Woman, the Sensitive Father, consciousness-raising and Marin County ad nauseum. Shoot the Moon has them all, again. The film presents an attractive nuclear family falling apart into a cliched state of modern entropy. Shuttling between Osterizer and station wagon, Diane Keaton oozes domesticity as much as she radiates pure will in Reds. But Faith Dunlap is a much less interesting woman and wife than Louise Bryant, and provides a much less challenging character for Keaton's talents. Albert Finney portrays her husband George, the archetypal, egotistical-yet-vulnerable San Francisco writer. They bicker in a picturesque old clapboard house softly nestled in the bucolic mellowness of northern California. Of their daughters, the three younger ones giggle, fight and roll their eyes throughout, as if the movie were a 90-minute toothpaste commercial ("Oh, Mom, do we hafta go to bed?"). Dana Hill, though, makes the oldest sister the most moving character in the film. Her tough, intense performance creates a girl almost too savvy and outspoken for a real 13-year-old, yet always believable. Recast from her point of view, the film could have added something truly new to the present glut of divorce movies. But instead we get more of the familialy familiar, watching from an adult's-eye view as both the husband and the wife take up with lovers who are deeply flawed as their shallowness will permit.

Of course, Faith and George almost get back together, while we, an audience enlightened by years of such cinematic breakings away, know that we are supposed to cheer for Faith to strike out on her own. In a scene that dogmatically explicates the all-too-predictable complexities of life, George confesses that he never appreciated the difficult role of wife and mother, that he was never around to be a good father, wrapped up in his work as he was. His attempt to become Alan Alda comes too late in his marriage to be relevant, and too late in film history to be interesting.

YET, SHOOT THE MOON'S rehashing of the whole litany of mid-life problems is at times interesting, even in its honesty. There are no euphemisms in this film. Director Alms Parker creates scenes of domestic violence that show exactly how the destruction of china and glass is only an attempt to preserve the fragile emotional architecture that overcivilized types like these construct within themselves. When George faces off with Faith's working-class lover in the final scene, the genteelly mad writer smashes his world of material comforts to bits in order to get back at his rival--who, lacking such possessions to act as intermediaries, answers with direct, personal violence to George himself. Neither is honorable, both are barbaric, and the movie ends on a note of human despair and isolation that transcends-temporary social cliches.

In general, though, the movie, dates and limits itself by the very details that make it so topical. Parker narrates almost every scene with overworked Top Forty hits of the late seventies. When the deepest emotional conflcits of a character can be completely explained by Eagles' lyrics, he is surely a child of his times and little more. The redundancy of the lyrics is embarrassing; when Faith's new man, a square-jawed hunk straight out of a Winston ad, starts to make the moves on her, the Stones burst into the living room with "Don't play with me 'cause you're playing with fire..." and the rest of the song's lyrics explain the obvious class difference in their relationship. One use of music that in particular teeters between the heavy-handed and the affecting is the repetition of the Beatles' "If I fell in love with you Would you promise to be true... 'cause I couldn't stand the pain." First, as George packs his things to leave, he and Faith sing the song in French, in happy reminiscence of honeymoon days in Provence. Is the irony meant to come through only to those educated in French, or is it assumed that every viewer has the lyrics deep enough under his pop-cultured hide that they are aroused just by the melody? Then Faith must sing it again--now translated into English--while alone in the bathtub, choked up by pain which is merely cheapened by rhyme. These banal songs are not merely the underpinnings of the sensibilities of these characters, but, sadly, the only form in which they can express themselves. Even when she's not singing. Faith utters profoundly empty phrases such as. "You helped me grow from a girl into a woman... I sang all the music but I forgot the words."

Shoot the Moon is an adequate mirror of our times--but not much more. It tells us little about ourselves that we have not been told before. At least it offers no easy answers. But its topicality limits it, and its very timeliness will soon date it. It is among the best of a boring genre.