As always, Amis's aim at the modern world, not to mention eternal human foibles, is dead on.
—Los Angeles Times
After the early splash with Lucky Jim, Kingsley's books got better and better, until a peak in the late 1960s and early 1970s, when he published The Green Man; Girl, 20 (my favorite); and Ending Up.
—Geoffrey Wheatcroft, The Atlantic Monthly
In Girl, 20 the character of whom Amis most disapproves politically is also made irresistibly charming, while—this is a really brilliant knight's move—the activity on which Amis himself had expended the most time (adultery) is shown by the actions of this very charmer as destructive to all parties.
For satiric ends the cast of characters has been adroitly shaped to expose a sort of folie a deux in which youth and an aging misleader of youth contribute equally to the mischief.
—The New York Times
I never found Lucky Jim—which launched Kingsley Amis—all that funny, but Girl, 20 is. It's one of those deft comedies the British seem to specialize in—a story that makes us laugh without being outrageous, manic, obscene, anti-patriotic or ethnic. It satirizes society without trying to bring it crashing down around our ears. It does not smear the Absurd like catchup on everything in sight. There is no gimmicky situation to set you thinking of Alan Arkin or Woody Allen. Its effects are derived mostly from its characters, who are all recognizable contemporary types. Their actions are funny not because they are inconsistent—the famous non sequitur syndrome invented by American wits—but because they are not, because these people keep plugging away, with varying degrees of ingenuity and success, at the peculiar, but not unusual stratagems for getting what they want.... Sir Roy is a first-class character, possibly Amis's best.
—Anatole Broyard, The New York Times
In his rollicking novel about the absurdities of the Sixties, Girl, 20, Kingsley Amis created a character who responded to each outbreak of pseudery with a phrase that he loathed. 'School of Thought!' he would exclaim; or 'Christian Gentleman!'
—The Daily Telegraph
In this book Sir Roy Vandervane at 54 embodies the best of the past, in that he is a talented symphonic conductor, good violinist, knowledgeable composer. He is also selling out to the future and the present, as represented by his long hair, his rich man's radical chic, permissiveness, with-it views on everything including rock music, and above all a bird named Sylvia who is just one-third as old as Roy.... This precocious little horror is a successful creature, one of those arrogant bullies of spontaneity who will imply that you are fascist if you make unhip remarks like 'what time is it' or 'where are we going?' Amis scores such precise hints as having Sir Roy guess wrong 'about what Sylvia would like to do,' itself such a substantial proportion of her total outlook upon the world.
—Robert Pinsky, Los Angeles Times
His novels of the late 1960s and early 1970s, which was in many ways his most confident and interesting period, include two powerfully expressive, minatory masterpieces in Ending Up and Girl, 20.
—Philip Hensher, The Spectator