Timing is everything in the theater, and it has been particularly hard on playwright Hamish Linklater’s Whirligig. Actress Moira Tierney, originally part of the announced cast, dropped out due to a scheduling conflict. (Tierney should have been wonderful in the role of a compassionate but on-edge mother, whose young adult daughter is dying from drug addiction.)

The second timing problem is worse, though I assume it’s coincidental. Whirligig is likely to remind you of other recent works, and the comparisons aren’t flattering. The first is Manchester by the Sea, which shares a few significant features with Whirligig, including its Massachusetts setting, and its running motif of broken families with haunted pasts. (I should also say that Manchester’s world is far more hard-scrabble—the drug problems that run through Whirligig cross various social class boundaries.)

Whirligig also looks like NBC’s current blockbuster hit, This Is Us. In this case, the milieu is different, but the similarities are even more striking—a fractured narrative structure that moves back and forth in time; characters whose storylines intersect in unexpected but too tidy ways; and a central theme again immersed in family drama and imminent death.

None of this precludes some misty-eyed enjoyment, and Whirligig has some winning qualities. The deal breaker for me (as with This Is Us) is mawkishness, which here is compounded by Duncan Sheik’s sentimental guitar music, suitable for a Lifetime movie.

The plot of Linklater’s play is actually quite simple—it’s the study of a family—divorced parents Michael (Norbert Leo Butz) and Kristina (Dolly Wells)—whose lives are ripped by the final illness of their daughter, Julie, the high school good girl who succumbed to drug addiction. Scenes at Julie’s hospital bedside, at home, and around their town unleash unanswerable questions and emotional revelations.

Along the way, there are some sweet character vignettes, expertly drawn by both the writer and the cast. Michael is a theater teacher, whose infectious enthusiasm imprints his students for years after; there’s also a handsome young doctor, Patrick (Noah Bean) whose path to medical school was thornier than you’d expect.

But Whirligig is circuitous and overwrought, and further hampered by a whimsical overlay involving the town outcast, Trish (Zosia Mamet), who spends a lot of time sitting in a tree, saying coy things to Derrick (Jonny Orsini), Patrick’s brother, who apparently did not get the brains in the family. The shift in tone makes little sense. (Also, when I see Zosia Mamet on a tree branch, I want to reach for a saw.)

Up a Tree: Zosia Mamet and Jonny Orsini in Whirligig, New Group Theatre at Signature Center. (Photo by Monique Carboni)

Bean, Van Patten, Alex Hurt (playing the local bartender), and especially Orsini are appealing performers; their easy, artless manner suits and even enhances Linklater’s work. Wells, who was brought in to replace Tierney, has an interesting presence, but her brittle Britishness feels out of place here. Butz is terrific, but his mannerisms are strikingly similar to his work in Bloodline (and the last thing you want in Whirligig is another reminder of episodic television).

Then there’s Mamet, whose tear and mascara-stained face adorns Whirligig’s program and poster. Playing an addled, drug addicted flake, Mamet’s quirky presence is appropriate. But her randomly weird line readings and distracted affect look less like character choices than an actor’s struggle—she comes off here as an amateur on a team of professionals.

Derek McLane’s eye-catching, almost magical scenic design captures the complex tonal blend of romance, whimsy, and realism far more fetchingly than Linklater’s script does. Director Scott Ellis keeps the action moving via a stage turntable—it, too, mimics the script in providing some intriguing overlap between individual scenes. But though Whirligig spins and spins, Hamish Linklater’s bumpy, overwritten play never finds an anchor.

The Whirligig plays through June 18 at Signature Theatre in New York. For more information, visit the website.