You’ll have fun at Grumpy Old Men.  Certainly, the day I saw it, the audience was delighted.

Turning a movie into a musical can be much more challenging than it seems. The musical Grumpy Old Men, now at Seven Angels Theatre in Waterbury through March 24, demonstrates the hurdles.

The hurdles include how much of the movie’s plot to retain, whether to eliminate or add characters, and should the plot be updated to modern times.

The original 1993 hit film starred Jack Lemon, Walter Matthau, and Ann Margaret. It was set in the present; two retired men (Max and John) who live next door to each other in a small Minnesota town have been feuding for decades. A new glamorous widow (Ariel) moves across the street from them, and the two widowers are both fascinated. The movie also included each man’s child (one son and one daughter) and their concerns about their fathers and their own thwarted relationship.

The creators (Dan Remmes – book, Neil Berg – music, and Nick Meglin – lyrics) have kept most of the plot, plus they have added a character.

The result is a show that is so crammed with plot points (and characters) that the development of many of these is barely sketched. This gives the actors playing these roles little to work with. On the other hand, Max and John have so much backstory that it just seems like they both have had incredibly unlucky/hard lives.

Most of the humor is of the middle-school-boy type – lots of insults and adolescent sexual innuendo. How much of this you find funny or just too much depends on your sense of humor and how much seeing grown men call each other a variety of offensive words is enjoyable. How many sexual jokes do you want John’s father, who is ninety, to make? For me, it was way overdone.

While the creators made some mistakes, the fine cast in this production doesn’t.  Semina De Laurentis, the co-director of the show and artistic director of the theater, has assembled a cast that includes seven Equity performers with extensive credits, plus several actors who have extensive non-Equity credits. The performances reflect this experience and talent. De Laurentis and co-director Janine Molinari keep the large cast on point.

De Laurentis plays the new character; Punky, the cousin of Chuck, the owner of the local bait shop. Punky is a cross between Gracie Allen and Goldie Hawn, spouting constant non-sequiturs. It’s funny, but I have little understanding of why the character was added.

Retained from the movie is Snyder, an IRS agent with a diabolic character who is pursuing John for a huge past-due tax bill. Here, Snyder is a vampy female agent, well played by Marcia Maslo.

But the success of the production depends on the three main characters: John, Max and Ariel. They all shine.

As John and Max, Gary Harger and Rob Bartlett are oil and water. Harger, as John, uses his tenor voice to full advantage; his solo – “When No One’s Around” – and his duets with Ariel are delightful. He even throws in some graceful movement. Harger lets us see that beneath the surface, John is a wounded man. It is a convincing performance. Bartlett is the rougher Max. He also captures the character’s rough exterior and does well with “In Like Flynn,” a more comic song. (Does anyone still know what that phrase means? Or that it refers to Errol Flynn?). As Ariel, Susan Kulp is graceful, lithe, and makes the most of a part that, in reality, doesn’t make much sense. She also has way too much backstory. You only really hear her sing in her two numbers with John.

Semina De Laurentis carries off Punky’s off-the-wall cluelessness well. The show is blessed with good performances by Al Bundonis as Chuck, the bait shop owner; Josh Powell as Max’s son; Marcia Maslo as the IRS agent, and Len Fredericks as John’s father.

The cast is backed up by a five-piece band.

Overall, this Grumpy Old Men will leave you anything but grumpy. But you may leave the theater wondering about the decisions the creators made.

For tickets, visit SevenAngelsTheatre.org