Two-and-a-half hours of unalloyed whimsy is a bit much, even for the Alley Theatre. Two-and-a-half hours of warmed-over Thornton Wilder-lite whimsy is way, way too much.

We are already blessed by the best of his best with Our Town and The Skin of Our Teeth, two of the most distinguished masterpieces of the theater, neither of which refuses to age. No wonder he left The Emporium unfinished for decades. He had already written it (and written it better than anyone else could have) in those former great works.

After Wilder's death in 1975, his nephew found boxes of unpublished material – diaries, notes, letters – that he then donated to Yale University. One box languished there for years until young playwright Kirk Lynn doing research on Wilder, stumbled across an unfinished script called The Emporium, which Wilder had worked on-and-off for years.

What he found were many drafts of the play. The play was hardly unknown, for Wilder had laid out in ultra-detail his working methods in private journals that had been subsequently published as an appendix to “The Journals of Thornton Wilder: 1939-1961.” The letters to himself are perhaps the most intricate account of how a playwright battles to produce a piece of dramatic fiction. After a full year of this structural struggle, Wilder had numerous versions of his nine-scene Everyman play, but he wasn't satisfied with any of them. He put all his notes and sketches away in a box and forgot them. But the surprise, of course, was discovering anything “new” by Wilder, even one left incomplete.

Lynn secured permission from the Wilder estate to finish the play in whatever form he wished, and that is what we see on the Alley boards. There's no disguising this is a deeply-felt Thornton Wilder work. It is replete with his hallmarks: an extreme theatricality that uses a Narrator who speaks directly to us; audience participation as bleating sheep, or hissing the villain, or taking a survey during intermission to tell the actors what scene to perform next; the quotidian made universal (perhaps the most Wilderesque trait of all); the quest for meaning, or love, or family, or anything really that makes us human; and a heart full of admiration for all regular people who don't appreciate what life is until it's gone. The small writ large. The little things that are more important than anything else. This is classic Wilder territory carved in capital letters. It's all here in Lynn. But it's just a retread, though. Been there, done that.

Lynn spices up the basics with contemporary references, like a decades-old shout-out to Honey Boo Boo or Birraporetti's restaurant around the corner from the Alley, but that doesn't help much. The infinite doesn't require such puny or punny references. We got the theme the first time. The mysteries of life were laid out perfectly in his previous work by the shelling of peas on a porch, moonlight caressing young love, the quick-as-death passing of life, the beautiful sound of a horse clop or a faraway midnight train whistle, a pet dinosaur as the Ice Age rages. He was a traditionalist at heart but loved the new. His department store-as-life was old news to him by the '50s.

Yes, if Our Town, Skin of Our Teeth, or the novels The Bridge of San Luis Rey (which in 1927 propelled Wilder into superstardom) or The Ides of March had never existed, then The Emporium might stand out in stark contrast with its heady form, its mystical dive into the deep, its Candide structure of innocent abroad. But we already have these, know them. Do we need a watered-down Wilder that sounds like a parody of Wilder?

This “world premiere” is saved in great measure by its sprightly production. Christopher Salazar is too old to play ingenue John; mugging does not become him. He's too stagy, and not once do we believe that the exceptionally photogenic and most natural of actors Raven Justine Troup would fall for him. Director Rob Melrose surrounds him, almost buries him, among some fine character work from the others.

Sally Wingert, as haggard farm mother, strict store employee, slatternly boarding house keeper who strews poisoned cheese at the feet of the audience to rid her establishment from rats, or a rundown, past her sell-by-date bride-wanna-be, is a wonder. She commands attention and gets it easily with a quick costume and wig change. Voilá, here comes a completely new character to beguile us. She brings smiles constantly.

And David Rainey employs all his prodigious theater wiles to lure us into his comic orbit, croaking devilishly as the brutish farm dad; yelling at us, the audience, as if we're Dickensian orphans asking for more; or as the decrepit owner of the Emporium's rival, Mr. Craigie. Rainey knows exactly when to caricature and when to play it straight. The others play it funny: Shawn Sides, Elizabeth Bunch, and Shawn Hamilton round out the fine cast.

But, really, it's Troup who sells this show with her quiet dignity, soft allure, and appealing style as John's love interest, Laurencia. She has haunted us in the Alley's Seascape and Amerikan, 4th Wall's Sanctuary City, and TUTS' Spring Awakening (she had one song and stopped the show cold). Her stage presence is magnetic, and her calm portrayal of someone much older than her years is eminently hypnotic.

The physical production in the smaller Neuhaus Theatre is another knockout for scenic designer Michael Locher, costumer Raquel Barreto, and the exquisitely subtle sound design from Yezminne Zepeda. Murals as if from the WPA ring the marbled walls; there's a hint of a coffered ceiling in this play-within-a-play. Was I hallucinating or did the hands on the large clock in the department store go backward, as if to slyly tell us that time was reversing? This is one of the subsidiary Big Themes in Emporium, which is only made clear at the end.

“This is how you keep going,” we're told. You “keep looking” for life and live as fully as you can, even when you think you're not living at all. Some make it, some don't, says Lynn /Wilder. But we all start out like that orphaned baby abandoned on the steps. No matter what life throws at you, keep going.

It takes 2½ hours to find this out, but better late than never, I guess.

The Emporium continues through June 2 at 7:30 p.m. Tuesdays through Thursdays; 8 p.m. Fridays and Saturdays; 2 p.m. Saturdays and Sundays; and 7 p.m. Sundays at Alley Theatre, 615 Texas. For more information, call 713-220-5700 or visit alleytheatre.org. $51-$74.