This movie was not bad, per se. But like the two best MCU films immediately before it, Avengers: Endgame & Spider-Man: No Way Home, it's more entertaining, due to payoffs from long-established characters and storylines (in the case of the latter, including some not actually made by Marvel/Disney), than a well-made film.

It's not a secret that James Gunn, the creative force behind the Guardians trilogy has parted ways with the MCU, even to someone who does not follow the behind the scenes stuff, like me. What I do know is that Gunn got "cancelled" by Marvel over some of his old material being dug up and recirculated - the content of which, or degree of offense, being still unknown to me - and IIRC, the lead actors of the films came to his defense, possibly even refusing to continue work on subsequent films in the series without him, and he was eventually restored to a state of grace, only to go on to make The Suicide Squad, an attempt to pave over an earlier film of practically the same name, less the article for Marvel's main competition, DC. In doing so, he managed to produce the third Harley Quinn movie and the first that was not absolute dogshit, which, to the beleaguered DC film franchise, made him appear the cinematic equivalent of King Midas, so he was given the job of being in charge of the whole thing, which, to date, seems to primarily consist of yanking Henry "Superman" Cavil's chain. So clearly, all is not forgiven between Marvel & Gunn, or if it is, the best we can say is that the divorce is amicable.

What this chain of events did to the production and creative decisions behind Guardians of the Galaxy, I could not say. I can't help but note that six years have elapsed between parts 2 & 3 of the series. By contrast, Iron Man (5 years), Captain America (5 years), Thor (6 years) and Spider-Man (4 years) all saw equal less time between their first and third movies, than Guardians saw between their second and third. And this movie also feels...messy. Ostensibly, given Gunn's presumed departure, this should have been the conclusion to the trilogy, especially given the characters' peripheral-at-best involvement with the rest of the MCU/Avengers storylines (and no indication of any current throughline for the rest of the MCU to alter the trajectory of the Guardians' trilogy or force them to leave their arcs open to merge with the big picture). And the end of the film suggests as much. It ends like it is the end of the saga, but it's simply that there is not much indication in most of the film that any kind of conclusion is being addressed. What this feels much more like was they went into it intending to focus more on the backstory of Rocket and his place on the team, and then swerved it into a finale as Gunn's deteriorating relationship with Marvel made it plain he was not going to being doing another one after part 3.

The most effective part of the movie is Rocket's stuff, genuinely emotional and even suggesting reasons for some of Rocket's quirks (his obsession with prosthetics, his denial he is a raccoon) being more tragic than the humorous purpose to which they are put. There are also moments of character development between the other comic relief aliens who have generally taken a backseat to Starlord and Gamora in prior installments, but these can be handicapped by the negative aspects of the movie.

And the negative aspects have to do with the execution of the plot, and the way it forces a lot to get to the finale and link up with the Rocket arc. First of all, rather than a rag-tag band of misfits, the Guardians are now an over-powered invincible kill team. I was at least a little bit under the impression that Starlord, Kraglin, Mantis, and possibly Gamora, were possessed of ordinary human limitations in strength, endurance and injury resistance. In this movie, they are buried in so many layers of plot armor (except for a couple of scenes where they are not) that there is seldom any real tension about their fates. That's not what you want for a concluding film, the one entry in a series that supposedly has the creative freedom to give the heroes dramatic deaths since they will no longer be needed to sell tickets (and of course, things like memories and visions have not prevented Michaels Rooker and B Jordan from reappearing in 2023 MCU films as their characters who allegedly died in the last film in their respective series). Even one moment of an apparent tragic death near the end is offset because you can't help but notice that the character's death is both reminiscent of similar moments of peril in the other two films, and only possible due to an inexplicable lack of something generally present for that character, and which one would think the prior incidents would have made imperative they make an effort to keep on hand. And a humorous visual also deflates much of the tension and pathos from that scene.

That ties in to another problem, which is the self-deprecating humor that has become part of the Marvel brand (despite the relative absence, or at least much more restrained deployment, in the films which made the MCU a success, in defiance of all expectations). This is arguably unfair, as the Guardians have always been a much more cartoonish and comedic series than the mainstream films, and nonetheless are much lesser offenders in this regard than most films post-Endgame, but it IS still a Marvel film and a significant aspect of the relationship between the two leads of the series is radically altered by the events of the Guardians' foray among the Avengers. You can't help but be reminded of the farcical scripts of Thor 4, Dr Strange 2, and Ant-man 3. Drax's literalistic comprehension and ignorance of social cues or idiomatic expression has Flanderized the character from a tragic survivor to a buffoon, which is lampshaded but not really addressed in the film. In fact, when Drax is confronted with the implicit significance for his character, the confrontation is immediately and literally erased.

On the other hand, a great deal of effort is made, largely successfully, to give Mantis more interiority and make her a bigger contributor than simply another punchline partner for Drax. Nebula is fully integrated into the team, and has, in light of Gamora's death in Infinity War, and Starlord's reaction to it, become a major factor holding it together (along with Mantis' efforts).

Another problem is the film's addiction to music. Earth music of the late 20th century features excessively and prominently, characters are constantly listening to iPods playing it, or reacting without comment to it coming over a loudspeaker or a ship's sound system, so that you can't help but notice it, and if it's not to your taste (like me), it's annoying and distracting. I liked literally one song I heard in this ( "Badlands" by Bruce Springsteen), and it was played over the end credits, but only after making us listen to the I'll-be-thrilled-if-I-never-hear-it-again "Come and Get Your Love". The villain is also revolting and contemptible, and so psychotically over the top he hardly feels like a threat. Indeed, most of the danger in the climactic (and overlong, another Marvel brand feature) battle/action scene has to do with the threat to innocent bystanders and is exacerbated by the ineptitude of the team themselves, than by any real notion that the villain might be a threat to our heroes.

It's also worth noting that the movie expects us to be invested in the danger to innocent bystanders, necessarily, having spent much of its runtime treating the heroes like they're made of rubber, after at least two battle scenes in which collateral damage to places and people the Guardians SHOULD care about, is completely ignored. Part of the peril in well-done space combat sequences is the relative danger even the smallest damage to a spaceship can pose to its occupants. Star Wars Episode 3's opening battle is often criticized as cartoonish, but in one incident, where enemies were threating a protagonists' ship with hand-to-hand destruction it was presented as a mark of extraordinary piloting skill that they were defeated by scraping them off the ship by flying it close enough to another vessel to do so, without crashing. A similar solution to a similar problem in this film is tossed off much more casually, to the point that, again, you are not seriously impressed by the impact, literally and figuratively, of crashing a spaceship, because, what the hell, nothing stops these things from flying or hurts the occupants.

What the movie does well are a few genuine feel-good moments, especially the team-up to effect the ultimate defeat of the villain and the way it depicts the extremes to which the team are willing to go for one another, despite the legitimate, and established personal problems between the members (as opposed to the clash of personalities and priorities that existed in the first film, prior to their formally becoming a team). Many of these are, unfortunately offset by other scenes that abuse slo-mo for dramatic cool pose shots or blatant emotionally manipulative tropes that make the use of Baby Yoda in Star Wars seem restrained. The cartoonish nature of the action also distracts you from the grim reality of the extremes the Guardians are ready to go to. It's not quite the failure to maintain a consistent tone that afflicted "Thor: Love and Thunder" or "Ant-man and the Wasp: Quantumania", it's more like a kind of fridge logic, except instead of realizing on second though that a plot element does not make sense, this film makes you actually realize, "wow, having to pull the trigger on the love of his life to keep a secret from Thanos has really cut Peter loose from his previous restraint, despite his nominal lip-service to minimal bloodshed" only in hindsight.

And speaking of Gamora, while the film, unlike almost EVERYTHING else in the MCU, does not handwave what the death toll of Infinity War should mean, the way it plays out does not feel true to the character. The Gamora in this film is not the one Thanos sacrificed to acquire an Infinity Stone, she is, in fact, the Gamora of the alternate timeline from which Rhodes and Nebula stole the GotG stone, which means she should basically be the character from the first Guardians movie, and she isn't. IIRC, that Gamora was the responsible one, the one concerned about more than her own survival or profit or revenge, and fighting for the greater good, whereas this one DGAF, and is more interested in running with the Ravagers, only participating in the plot of this film for profit. It does make sense that, yes, she would not have "our" Gamora's attachment to any of the Guardians except Nebula, or would resent Peter's attempts to cram her into the hole left by "his" Gamora's absence, but otherwise, the character feels like she was just changed to be a reluctant hero for this film.

It's a somewhat too-long, loud and messy product, possibly trying to do too much or too little, but it's not as offensive to logic and plot comprehension as so many genre films these days, and is not unenjoyable or regrettable in hindsight as most Marvel or Disnified IPs in general are these days. At least you feel, unlike Thor or Ant-man, we're getting out clean. If you don't mind 2.5 hours, it's not a bad visit to the theater.

EDIT: I also realized, I forgot to mention some stuff. The golden arrogant people from the last movie, or at least their leader, played by Elizabeth Debicki, is back, and the teased weapon she was preparing for revenge against the Guardians is revealed to be a sort of superman version of them, played by Will Poulter, aka, that guy with the weird eyebrows (his erstwhile love-interest from "We're the Millers", Molly Quinn, has a blink and you'll miss it role as a Ravager, and HER TV dad, Nathan Fillion, has an excessive role as the head of security for a scientific facility the Guardians break into, for no apparent reason other than to have Nathan Fillion being Nathan Fillion). He is as powerful or as vulnerable as the plot need him to be in any given moment. Blasting through walls or out of restraints with ease, and smashing into people without doing any meaningful harm. Maybe he is a well-known comic book character, maybe he is being set up for a more important role down the road, but as the payoff to the implied threat from continuity, he's a bit of a wet fart, despite being tied in to the main villain of this film.

Another thing, like the Fillion cameo that gets way too much screen time is Kraglin, who happens to be played by James Gunn's brother, and his interactions with the dog in the space suit, who is now sapient and has a Russian accent and telekinetic powers. The resolution of their arc is utterly predictable in all regards and takes much too long to accomplish given how obvious it is.