Two years after his failed Oscar-bait “Maestro,” Bradley Cooper returns with his third directorial feature “Is This Thing On?”, a low-key, personal dramedy featuring Will Arnett in a raw, dramatic role.

Although Arnett is the star, “Is This Thing On?” is Cooper’s film. It is also starkly different from Cooper’s previous movies. In a directorial 180, Cooper swapped out ambitious filmmaking for something much more down-to-earth, crafting a bittersweet character drama. Where Cooper’s other films — “A Star is Born” and “Maestro” — were high-budget, epic stories stretching years, “Is This Thing On?” is deftly low-budget and contained. For some scenes, Cooper himself serves as the camera operator, shooting handheld, up close and personal. The shots make it all feel natural and chaotic, and the small, personal stakes large and meaningful.

“Is This Thing On?” is all the better for its smaller-scale approach. The camerawork and other visual creative decisions made by Cooper are well done and engaging, drawing and absorbing the viewer into the film’s world and the characters’ mindsets in a way only a lower-budget, thoughtful film can.

If one thing unites all of Cooper’s movies, it is that interpersonal relationships are at their centers.

Arnett plays Alex, a man who has idly let life pass him by to such an extent that his wife Tess, played by Laura Dern, casually initiates their amicable separation while in the midst of brushing her teeth before bed. As Alex grapples with his newly separated life, he inadvertently stumbles upon the New York City comedy club scene in the Lower East Side, a rejuvenating thrill that imbues Alex with passion. As Alex becomes an amateur comic, his new and old lives come together and he must come to terms with his relationship with Tess and his own failings.

If one thing unites all of Cooper’s movies, it is that interpersonal relationships are at their centers. In the latter half of “Is This Thing On?” Dern and Arnett shine, grappling with their roles in their broken marriage. The film shifts from comedy to drama as Alex and Tess struggle to reconcile their love with their personal history and heartbreak, and the consequences of action and inaction over their two-plus decades of marriage. It is further complicated by the “will-they-won’t-they” of Tess and Alex giving each other one more chance. Cooper excels at relationship drama, and here, it is the highlight of the film.

“Is This Thing On?” is a slow burn, but really hits its groove about halfway through as Tess and Alex’s fates converge. The tedium and subtlety of the film may split audiences; I know the audience at my screening was torn, with some of my fellow theater-goers left lukewarm by the film’s end. However, I thought “Is This Thing On?” was a legitimately cathartic, funny and intelligent film. There are many visceral and thought-provoking scenes that enhance the film’s themes and still stick out in my mind and make me laugh, cringe and feel something after the screening.

It would be remiss not to highlight Arnett, of “Bojack Horseman” and “Arrested Development” level fame, headlining this movie. Arnett portrays the tenderness, heartbreak, confusion and anger of his character Alex exceptionally well, making the character his own. This is Arnett’s first leading dramatic role in a film, and he kills it.

There may likely be some well-deserved awards buzz for both Dern and Arnett’s roles here.

Dern also gives a worthy companion performance as Arnett’s ex-wife, embarking on a path to regain some much-needed and desired purpose. She is extremely well-realized in her role, and the film does a great job of not playing one side but portraying both characters’ feelings and perspectives. There may likely be some well-deserved awards buzz for both Dern and Arnett’s roles here.

“Is This Thing On?” also joins the canon of New York City movies, featuring iconic sites such as Grand Central Station, subway trains and the Comedy Cellar, of course. It captures the bustle, lighting and atmosphere of the city well, elevated by a solid musical score — although the environment could have been embraced more.

Additionally, five or so minutes could have been shaved off the movie’s runtime, and some scenes come off a little too vulgar, including one in particular that flippantly discussed hookups. However, by its end, “Is This Thing On?” shows its true colors as a sweet film about a marriage falling apart and coming back together, and a simple man’s catharsis through comedy and realization.