Chris Pratt and Zoe Saldana in "Guardians of the Galaxy Vol. 3."
CNN  — 

In hindsight, the most unlikely hit among Marvel’s parade of them was all about the unlikeliest of families. “Guardians of the Galaxy Vol. 3” drives home that point, with a boisterous and often emotional sequel that feels very much like a true conclusion, fueled in no small part by writer-director James Gunn having migrated his talents over to rival DC.

Building franchises around more obscure heroes always represented the biggest risk in Marvel’s cinematic plans, which made the success of “Guardians” in 2014 and its less-satisfying sequel a minor miracle. As evidence look no further than “Eternals,” another super-team that (while meriting an asterisk due to the pandemic) didn’t fare nearly as well.

The key to Gunn’s earlier movies relied on a mix of abundant visual energy, distinctive characters, cleverly incorporated songs and no small amount of sheer goofiness. All of that is on full display in “Vol. 3,” as well as a darker thread that delves heavily into the past of Rocket (voiced by Bradley Cooper), the unnaturally savvy and bloodthirsty anthropomorphic raccoon, conveying an unexpectedly poignant animal-rights message in the process.

This “Guardians” begins with Quill (Chris Pratt) having become an emotional wreck because of his estrangement from Gamora (Zoe Saldaña), who returned post-blip with no memory of their relationship. He’s jolted from his misery, however, by a threat that forces the team to leap into action to save one of their own, which includes facing off against one of the more visually striking comics characters, Adam Warlock (Will Poulter), a creature with enormous power but an almost-childlike mind.

Pom Klementieff, Chris Pratt and Karen Gillan in "Guardians of the Galaxy Vol. 3."

Reinforcing the sense of the movie serving as an extended curtain call, Gunn – who, remember, was fired from the project over social-media posts, and later reinstated – repeatedly highlights the depth of the bond between key players, in a way that perhaps more than anything brings to mind “Toy Story 3.” Yet “Guardians” also revels in broadly comic exchanges between the hulking Drax (Dave Bautista), empath Mantis (Pom Klementieff) and serious Nebula (Karen Gillan), often approximating the banter of squabbling siblings.

That playfulness – recently illustrated by the “Guardians” holiday special – extends to the seemingly unlimited song budget, which has moved beyond Quill clinging to his childhood to setting an overall mood of warmth and nostalgia.

Other than being a bit too busy, and a little too long, the main quibbles would be somewhat underusing Warlock and the generic nature of the principal bad guy, a ruthless madman known as the High Evolutionary (Chukwudi Iwuji), although the villains have been a weak link throughout. The closing-credit sequences also fall in the barely-worth-sitting-through category.

Still, after some second-guessing about Marvel’s invulnerability thanks to disappointing results (creatively as well as commercially) for “Ant-Man and the Wasp: Quantumania” and to a lesser degree the “Black Panther” sequel, “Guardians” feels like a return to form on both fronts. And if it does close the books, at least for a while, on this series, give Gunn credit for bidding a fond farewell with both barrels blazing.

“Guardians of the Galaxy Vol. 3” premieres May 5 in US theaters. It’s rated PG-13.