Plot points from Black Panther are discussed below. Spoilers, etc.
Black Panther is unmistakably a Marvel Cinematic Universe origin film: competently executed with the house anti-style largely intact; solidly acted with a few well-choreographed action sequences that culminate in an un-rousing and sometimes-shoddy-looking CGI mishmash; and seasoned with a healthy dose of humor and inter-universe connections designed to appeal to those of us who have waded through the previous 17 entries in the indefatigable mega-franchise.
(Black Panther is definitely the greatest comic book movie of all time.)
Technically, of course, we've already been introduced to T'Challa (Chadwick Boseman), the Black Panther. The murder of his father, T'Chaka (John Kani), in a terrorist bombing supposedly perpetrated by the Winter Soldier (Sebastian Stan), was the instigating incident of Captain America: Civil War. T'Challa played a key role in aiding Cap's effort to take down Baron Zemo and help his friend Bucky Barnes.
(Okay, look, it's not the greatest comic book movie of all time, but it's definitely the best MCU movie of all time.)
But Black Panther serves as an origin story nevertheless—of a nation, rather than a character. As the film opens, the history of Wakanda is laid out in front of us. Founded atop a meteorite of vibranium (basically: magic metal), four African tribes came together to build a technologically advanced metropolis, while another tribe retreated into the snowy mountains. When colonialism arrived, Wakanda retreated, hiding its technology and sending spies out into the world to see what needed seeing.
(Fine, it's definitely one of the best MCU movies.)
The design of Wakanda is both intriguing and familiar. The sprawling streets are covered with graffiti and packed with markets and oddly dressed individuals, which may call to mind the battle planet from last year's Thor: Ragnarok. Black Panther, like Ragnarok, is unconcerned with the ground's-eye view of the world we are dropping into; we have no idea how the average Wakandan feels about the murder of their king or the ascension of T'Challa to the throne or the chaos that follows his crowning. The city's vibranium-infused technology hews nicely to Arthur C. Clarke's third law. There is no rational explanation for the advancements made by T'Challa's people thanks to the sound-absorbing, mutagenic metal upon which their civilization was founded. It just is. Go with it.
(Like, Black Panther is way better than Iron Man 2 or Thor 2 or The Incredible Hulk.)
One character who has no interest in just going with it any longer is Erik, a/k/a Killmonger (Michael B. Jordan). A Wakandan by birth, he has teamed up with Ulysses Klaue (Andy Serkis) to steal a vibranium artifact from a British museum—but he has his eyes set on a bigger prize than some ancient pickaxe. He wants the throne. And he's more than happy to kill T'Challa to take it.
(But you're high if you think it's not a tier below, say, Avengers or Guardians of the Galaxy or either Captain America sequel or Iron Man.)
In addition to having the greatest name of any MCU villain, Killmonger also has the most reasonable motivation. He believes Wakanda, as a society, has abdicated its responsibility to the people of Africa. When slavers rolled through the continent, Wakandans hid. When colonizers divided and conquered, they stayed silent. As oppression took root around the world in urban enclaves and rural expanses alike, Wakanda sat on its vibranium weapons and did nothing. Killmonger, accepting the lessons taught to him by his father N'Jobu (Sterling K. Brown), is, essentially, a black panther in the American sense: a black nationalist, a believer in black power, a radical and an extremist, a man committed to the violent overthrow of those who would oppress his people.
(That being said, it's the best origin film for one of the oddball, minor characters. Black Panther >>> Ant-Man or Dr. Strange or Thor.)
And Killmonger is more or less correct. Perhaps not in the sense of sending unstoppable vibranium weapons around the world to topple governments in America and the United Kingdom and everywhere else, but in the sense that the only way to fight imperialism you oppose, imperialism that would oppress you, is with imperialism of your own. Wakanda's refusal to intercede in its continent's affairs over the preceding half-millennium led to an unquantifiable amount of suffering. That Killmonger looks upon this legacy of cowardice with a sneer is not only understandable—it's admirable.
(It's probably about on the same level of Spider-Man: Homecoming, I guess?)
By film's end, T'Challa and his somewhat-Westernized sister seem to agree with Killmonger's point: Wakanda will no longer remain hidden, and a program of soft power will be undertaken to aid impoverished communities around the world.
(That's still very good!)
Jordan and Serkis, exuding charisma and charm, are the best aspect of the movie by a country mile. Jordan's swagger and Serkis's mad-eyed glint steal the show. Though I don't want to sell Danai Gurira (a/k/a Michonne, from The Walking Dead), short; she brings a lithe-yet-muscular physicality to her role as the head of the palace guard. And Letitia Wright, who plays T'Challa's sister, Shuri, is amusing as well. It's too bad that Forest Whitaker is little more than a deliverer of exposition here. And Boseman is a bit of a nullity; he faces the same problem that Evans faces in the role of Captain America, insofar as both characters are squares. T'Challa is upright and noble, to be sure, but kind of lame when he's not engaged in action. It felt like there was more fire in his belly in Civil War, angered as he was by the murder of his father.
(What I'm saying is that Black Panther is firmly in the second quartile of the Marvel Cinematic Universe: better than Ant-Man, not quite as good as Captain America: Civil War.)
The bottom line: Black Panther is a solid MCU movie, entertaining if somewhat disposable. If you like the rest of these movies—and everyone, even your humble reviewer, seems to like the rest of these movies—you'll probably like this one too.
(The mid-credits and post-credits scenes are pretty blah, to be honest; you could read about them after the fact and not miss too much if you don't feel like sitting through the interminable list of names of people you don't care about.)