Well, it ain't no Empire Strikes Back or even a Winter Soldier, but Captain America: Civil War knocks the socks off Avengers: Age of Ultron. It's was worth the matinee, probably even worth full price. I had fun, even if I wished I had multiple Marvel Comics wikipedia pages open while watching.
At it's core, the premise of this movie is, "If Iron Man and Captain America got in a fight, who would win?" (As of this writing, I still haven't seen Batman v. Superman, but I assume it's operating under the same premise.) On that level, It's Frankenstein Meet Dracula, Aliens vs. Predator or Freddy vs. Jason. The main job the writers of something like this have is coming up with a plausible reason for the two headlining characters to fight. The reason the Russo Brothers came up actually works surprisingly well.
Briefly... the Avengers (Now consisting of Cap, Falcon, Black Widow, Scarlet Witch, and Vision) go to Lagos, Nigeria to fight Crossbones, the random bad guy from Winter Soldier who, in his own words, "had a building dropped on his face." During the fight, a bunch of civilians get killed by a bomb Scarlet Witch deflects into a building while trying to save Captain America. Meanwhile, Tony Stark/Iron Man gets confronted by the mother of a kid who died in Sokovia, the fictional city Ultron laid waste to at the end of Avengers 2. Soon, Secretary of State Thaddeus Ross (William Hurt playing the same character he played in the Ed Norton Incredible Hulk) tells them that 119 nations have agreed to the Sokovia Accords which basically puts the Avengers under United Nations authority. Iron Man thinks they need to sign it, Cap doesn't.
Various Avengers take different sides. The most interesting dichotomy is between the Vision and Scarlet Witch who debate the philosophy of power, responsibility, and self-control vs. external control while kind of/sort of falling in love with each other. In the comics they eventually get married, and I kept finding myself thinking about the fact that he's an android and for all intents and purposes she's falling in love with a robot. She's fucking a robot. While this is probably where the culture is going, it kept distracting me.
Anyway in Vienna, the King of Wakanda is killed at the U.N. signing of the accords by a bomb seemingly set by Cap's old buddy Bucky Barnes aka the Winter Soldier. Wakanda you'll remember is the fictional African country where the rare metal Vibranium is found. Vibranium you'll remember (right?) is what Captain America's shield is made of, and what Ultron built his main body out of in Avengers 2. Cap goes off the reservation to find Bucky because he suspects something is rotten in Denmark. The Falcon joins him and Black Widow is torn. Meanwhile, T'Challa, the heir to the throne of Wakanda dons his Black Panther superhero suit with the Vibranium claws and vows vengeance on the Winter Soldier. The Black Panther is *awesome.* He steals the movie. I'm genuinely stoked for his solo movie directed by Ryan Coogler. (Fruitvale Station, Creed)
I mentioned a fictional metal three times in the previous paragraph.
So, the U.N wants to kill rogue Captain America and Winter Soldier who are now on the run together. Iron Man asks for 36 hours to bring him in. The middle of the movie is basically lead up to a big battle royale between two groups of Superheroes. Team Iron Man ( I can't believe I just typed that.) consists of Iron Man, War Machine (Don Cheadle's silver Iron Man), Black Widow, Vision, Black Panther, and Spider-Man. Team Captain America consists of Cap, Winter Solider, Falcon, Scarlet Witch, Hawkeye, And Ant-Man. I know it sounds like way too many characters, but it's pretty satisfying. The big fight itself is fantastic, with a very young Spider-Man providing a ton of comic relief. I don't know if this next reboot with save that particular ailing franchise, but the casting is great.
That's not the big climax of the movie though despite what the ads infer. The third act goes back to Bourne stye intimacy of the Winter Soldier. There's a lot more going on, including the machinations of Baron Zemo, a very human villain who's pulling a ton of strings in order to get to Moscow to where the Winter Soldier was created. I won't give away the twist ending, but it's satisfying. I'll also note that the climax of this movie doesn't involve some world ending calamity, which makes it 10,000 times better than any superhero movie that does.
Typed out, it reads like too much going on, but it works in every way that Age of Ultron didn't. RC says check it out.