Oh, Couples Retreat, you had so much promise.

Vince Vaughn’s latest has all the right ingredients: a stellar ensemble cast, including Jon Favreau and Jason Bateman, an intriguing premise and a gorgeous island backdrop. Why, then, does it fall completely flat?

The first 45 minutes or so don’t offer any warning signs, with all four troubled couples hesitantly embarking on a vacation to Eden, a resort aimed at repairing broken relationships. Uptight Jason conceives the trip as a way to mend his union with Cynthia (Kristen Bell), eager to corral the entire gang in hopes of a discounted group rate.

Shortly after the group’s arrival, however, things head south and the comedy morphs into an uninspired tutorial on relationship building. To make matters worse, this trend lasts for the remainder of the film. The sappy dialogue doesn’t do favors for any of the castmembers, so the presence of hilariously sassy Trudy (Kali Hawk) is a welcome relief. Everyone else is busy being serious with couples therapy and other un-fun stuff. Wasn’t this supposed to be a comedy?

Make your next island getaway a guys-only trip, Vince; it will be better for everyone involved.

2 stars

Directed by: Peter Billingsley

Starring: Vince Vaughn, Jon Favreau, Jason Bateman

Rated: PG-13, 107 min.