Shakespeare in the Park, as beloved a theatrical ritual as New York has to offer, nearly always scrambles to give its audiences some bang for their several hours spent queueing for tickets. Occasionally a director will punch up the Delacorte Theatre’s visual capabilities, but the typical strategy has been to cede aesthetic supremacy to Central Park and instead plunk a few famous names into the cast.

Despite the presence of two longtime television stars, including the luminous Lauren Ambrose (“Six Feet Under”) as Juliet, Michael Greif’s eye-catching but unwieldy “Romeo and Juliet” falls firmly in the former camp.

From the play’s first moments, Mr. Greif signals both the delights and the deficiencies of his production. As the entire cast assembles on Mark Wendland’s set, Christopher Evan Welch steps forth to declaim the play’s prologue. Meanwhile, a 70-foot wading pool rumbles and rotates behind him on a massive turntable. Now, Mr. Welch stuffs the role of Mercutio, the licentious comrade of young Romeo (Oscar Isaac), with audiencepleasing verve and whip-smart physicality. He even finds a few laughs — and a telling flash of anger — in the overdrawn “Queen Mab” soliloquy. But not even this supremely inventive actor stands a chance against the sight and sound of some two dozen stage actors walking over — and through — a spinning pool of water.

Water can be a fantastic theatrical device, evoking everything from sexual awakening to baptism to placidity. (“110 in the Shade” and “Eurydice” are two recent works to offer some of these shadings; 2001’s “Metamorphoses” offered all of them, and several others.) Water shimmers. It soothes. It makes actors’ clothes cling to them.

It is, in short, very hard to ignore. And so the pressure lands even more firmly on the director to provide performances and thematic heft to counter its elemental pleasures. This is where Mr. Greif allows his admittedly impressive visuals to swamp his sense of scale and pacing: The prologue’s promise of “two hours’ traffic of our stage” miscalculates by a solid hour. And his concept, like his ever-present pool, is shallow.

Shakespeare, William Hazlitt famously wrote, “founded the passion of the two lovers not on the pleasures they had experienced, but on all the pleasures they had not experienced.” The central tragedy of “Romeo and Juliet,” in other words, is one of quashed potential, a quality that Ms. Ambrose captures perfectly as she laments her post-marital but still pre-coital state: “Though I am sold, / Not yet enjoy’d.” (Of course, this fidgetiness may also stem from repeatedly traipsing through water while wearing little more than a slip on an unseasonably cool June evening.)

Here and elsewhere, her Juliet deftly conveys the unbidden anxieties and irresistible urges of adolescence; when she and Romeo part midway through the first balcony scene, confusion and possibly even shame flash across her face the minute she turns away. Ms. Ambrose’s beautifully realized performance displays Juliet’s ingenuousness — and all the heartbreak that comes with it.

Like his character, Mr. Isaac seems a bit at a loss when Juliet isn’t around: His earlier scenes have a slack, sing-songy quality to them, and a fiery confrontation with his hapless confederate Friar Laurence (Austin Pendleton) suffers from a lack of modulation. But he rallies during the tantalizing courtship scenes, giving Romeo a boyish, impulsive bravado that makes the instant attraction between the two entirely plausible. The previously formidable chemistry between him and Ms. Ambrose dissipates somewhat after they’re married at the end of Act II, though. (Make whatever joke you like here.)

This chemistry first flares up at the Act I masquerade, a scene Mr. Greif also uses to set up the wrathful temper of Juliet’s father, Lord Capulet (Michael Cristofer, himself a Pulitzer Prize-winning playwright); in both this tirade and the far scarier one that seals the young lovers’ fates, Mr. Cristofer holds the stage with surprising comfort. And Mr. Pendleton, another sometime playwright, radiates befuddled serenity despite a lingering case of the line flubs that plagued him in last year’s Delacorte staging of “Mother Courage.”

But Camryn Manheim — a longtime star of TV’s “The Practice” — works far too hard to find her laughs as Juliet’s Nurse, resorting to a dismaying array of shouts, snorts, and balled fists that nonetheless won over a substantial subset of the audience. And Dan Colman’s Paris and Brian Tyree Henry’s Tybalt offer little beyond buffoonish chivalry and seething rage, respectively.

Mr. Henry does, however, shine in the battles, which feature some of the finest work yet from the superlative fight director Rick Sordelet; the fateful sword fight includes a memorable three-on-one skirmish and a battle that rages over another character on the ground, followed almost immediately by an even more harrowing hand-to-hand battle.

This sequence draws some of its intensity from Messrs. Greif and Wendland’s omnipresent pool; the combatants splash and skid their way across the stage until Tybalt, with a crumpled majesty evocative of Robert Capa’s D-Day photographs, lies dead in the water. This image is mirrored in the finale, in which Mr. Greif’s haunting depiction of torch-lit carnage goes a long way toward overcoming a laggardly pace.

Much earlier in the play, Romeo likens love to

… a smoke raised with the fume of sighs;
Being purged, a fire sparkling in lovers’ eyes;
Being vex’d, a sea nourish’d with lovers’ tears.

Romeo and Juliet might easily have shed enough tears to create a sea of their own had the creative team not beaten them to it. By overshadowing that fire with his own ambitious but ultimately stultifying vision, Mr. Greif has done more than silence literature’s greatest pair of young lovers. He has drowned them out.

Until July 8 (Central Park, 212-539-8750).