Guardians of the Galaxy 3 is a thrill-ride of a conclusion to the James Gunn trilogy that, sadly, ends one of the best movie runs in Marvel's Cinematic Universe.

More than any other film in the long-running MCU series, the first installment in the Guardians saga took characters that were of little regard in the Marvel Comics world and made them into a highly successful, immensely popular part of the movie franchise. It's a testament to the cast, writing and direction, all of which played a role in its success.

Besides their own trilogy, the Guardians have appeared in movies with the Avengers and Thor, and they managed to hold their own. (They even put out a delightful holiday special that managed to be both silly and heartwarming and a whole lot of fun.)

In the third Guardians movie, the team is relaxing at their home in Knowhere, a space colony built in the head of a dead Celestial, when Adam Warlock (Will Poulter) comes to wreak horrible vengeance on them for past transgressions. Rocket, the team's tech-savvy, anthropomorphic raccoon, is badly injured, and when they attempt to heal him the team discovers a kill switch implanted in his chest that prevents a surgical intervention.

That leads them to the High Evolutionary (Chukwudi Iwuji), the evil genius who directed Rocket's evolution. And Iwuji gives a villain who is impossible not to hate, particularly during relentless scenes of animal cruelty that are incredibly hard to watch.

Besides Rocket (voiced by Bradley Cooper), the Guardians' team is leader Peter "Star-Lord" Quill (Chris Pratt), sentient tree Groot (voiced by Vin Diesel, staged by Austin Freeman), strong man Drax (Dave Bautista), the empathic Mantis (Pom Klementieff), former villain Nebula (Karen Gillan), lethal whistler Kraglin (Sean Gunn), psychic space-dog Cosmo (voiced by Maria Bakalova) and, reluctantly, the reborn Gamora (Zoe Saldana), who no longer remembers being in love with Peter. There is, despite their frequent bickering, a lot of great chemistry between teammates.

Credit where credit is due: James Gunn, despite personal controversies that almost ended his Marvel career prematurely and some questionable decisions now that he's handling the future of DC's movie franchise, has crafted a movie that is both hilarious and tragic. In GotG3, Gunn finds the delicate balance of humor and seriousness that eludes so many directors in the MCU franchise.

The movie boasts moments of incredible beauty and emotion. It is at times heartwarming and uplifting. It is sometimes laugh-out-loud funny. It also ratchets up the level of violence and death, with scenes that are heartbreaking and tragic. Gunn even manages to conjure tear-jerking pathos with a trio of utterly ludicrous animal hybrids: Lylla the otter, Teefs the walrus and Floor the bunny (voiced by Linda Cardellini, Asim Chaudhry and Mikaela Hoover).

The movie hits all the right notes. It's a fitting conclusion to the trilogy, which is without question one of the best and most cohesive sequences of films in the MCU.

It's a shame, knowing as we do that some of the Guardians cast members have already announced they will not reprise those roles. But it's heartening that at least one star has already made plans to return (if the post-credits scene is to be believed) and others are at least open to the idea. Maybe some of the others can be persuaded.