Saccharine holiday flick is better suited on the small screen.

Without the A-list cast and top-shelf director, “Last Christmas” would be a major hit on Netflix or LIfetime. But as a theatrical feature, where expectations are understandably higher, this romantic comedy is a subpar experience. “Last Christmas” is so sugary sweet that it would leave a bad taste in the mouth of even the most enthusiastic of Santa’s Elves.

Henry Golding as the mysterious Tom.

“Game of Thrones” star Emilia Clarke plays Kate, a reckless twenty-something who works in a seasonal store in London run by a woman who goes by Santa (Michelle Yeoh). Santa values Kate as an employee but, recently, Kate’s growing cynicism and self-destructive behavior has taken its toll. A fun montage reveals that Kate has burned bridges with most of her friends. To make matters worse, Kate’s singing career was cut short by a medical problem. But when she meets the kind and considerate Tom (Henry Golding), Kate’s prospects begin to look up.

Co-writer Emma Thompson is funny in the mom role.

The highlight of the movie is Emma Thompson’s performance as Kate’s mother, Adelia (Emma Thompson), an overly protective Yugoslavian immigrant. Thompson, who co-writes here, saves all the best jokes for herself. She adopts a thick accent, and her comic timing is excellent. The rest of the picture is tonally uneven, contrived, and flat-out lazy.

Folks that demonized last year’s Oscar winner “Green Book” could easily vent their anger on “Last Christmas,” as well. Part of the narrative concerns Kate’s work at a homeless shelter. If you’ve ever visited or worked at one of these important places, you will instantly recognize the artificial nature of the one depicted here. Kate steps in as a kind of savior of the facility. It’s positively wince-inducing. It’s unsophisticated filmmaking unworthy of theatrical viewing.

Michelle Yeoh as Santa.

For the last two holiday seasons, my daughter and I gleefully watched the latest Netflix Christmas offerings. These cheesy films are delightful time-wasters. Last year, we put them on in my office, while secretly wrapping presents, and these ridiculous movies provided cheery background noise. “Last Christmas” is best watched in that setting, where you only focus on the film sporadically, noticing the funny parts. But if you’re forced to sit quietly in a darkened theater, the cracks are magnified.

Trite and insincere, “Last Christmas” is a cloying cup of holiday sneer.