Guardians of the Galaxy is without a doubt the weirdest Marvel movie to make it to the screen yet—and it's mostly a good thing. The film centers on a motley band of companions who are (according to director James Gunn) "The Rolling Stones compared to The Avengers' Beatles." The movie takes pride in its irreverent subversion of standard comic-book self-seriousness, even more than the usual light-heartedness that Marvel's got on display. While other Marvel films feel like funny superhero movies, Guardians of the Galaxy is closer to a comedy set in outer space.
In 1983, the Earth-bound Peter Quill (Chris Pratt) is abducted by aliens immediately following the death of his mother. This launches the best running joke of the whole movie, that the film's "pop-culture timeline" ends in '83—thus we see Quill dancing around with a Walkman on a desolate alien planet and decorating his ship with little troll dolls. Fast-forward to 2015 and we meet Quill—or, as he likes to call himself, Star-Lord—who's taken up smuggling black market items.
But the thievery of an object called an Infinity Stone, an old relic of bunches of power, has got the most powerful forces in the Universe looking to kill Peter and the companions he picks up along the way—including the green-skinned Gamora (Zoe Saldana), an explosophillic talking raccoon named Rocket (voiced by Bradley Cooper), a tortured warrior named Drax (Dave Bautista), and a talking (sort of) tree named Groot, whose lone line—"I am Groot"—is inflected to perfection by Vin Diesel.
While I've got some niggling issues with the movie (which I'll get to in a second), I want to make clear how refreshing Guardians of the Galaxy is in a sea of movies like The Amazing Spider-Man 2 or Man of Steel, which feature roughly 1000% more brooding/sulking/angst than any person goes through in a year. Guardians is a fun movie populated by fun characters where fun things happen. The movie is fun is successful insofar as it's character based; Chris Pratt delivers an intensely Chris-Prattian performance, filled to the brim with wit, charm, and a perfect sense of comedic timing. Other actors get in on the fun, too—Bautista, for whom Guardians is his first major role, excels in the role of an over-literal warmonger (sort of a Conanio ad infinitum situation).
And Bradley Cooper is fantastic as the vaguely-Jersey raccoon science project, managing to do what few predominately film-based actors can and disappear totally into his role. Basically, at no point in the movie do you think "Hey, that's Bradley Cooper," except for the first time the character speaks—and even then, it's only to think, "Hey, that sounds almost nothing like Bradley Cooper."
The movie is seriously smile-worthy, largely due to the sheer number of jokes throughout. Hardly five minutes go by without something happening on screen that makes you crack a smile. But unlike the gag-heavy offering of something like 22 Jump Street, Guardians keeps its humor mostly character- and quip-based. Humor goes down much easier when it's one character saying a funny thing, rather than a drawn-out series of back-and-forths; as such, Guardians never suffers from the same comedic burn-out as something like 22 Jump.