Avengers: Age of Ultron is a masterful, albeit slightly flawed film that is a worthy addition to the Marvel Cinematic Universe (MCU).

It is a miracle that director Joss Whedon, who also made the first Avengers movie, was able to juggle so many characters while keeping their motivations clear.

Additionally, Whedon reveals sides of each character we hadn’t seen before. We see a vulnerable Thor (Chris Hemsworth). We meet the Maximoffs (Elizabeth Olsen and Aaron Taylor-Johnson), a pair of genetically modified twins, whose characters are both dutifully fleshed out by the end of the film. We learn things about Hawkeye (Jeremy Renner) that no one would ever suspect. We even learn more about the mysterious past of Black Widow (Scarlett Johansson).

The film also takes us around the globe with the heroes, who trek from Africa to New York to stop the villainous plans of the evil robot Ultron (voiced by James Spader), who is created by Tony Stark (Robert Downey Jr.)  to help the Avengers, but instead of helping them, the robot seeks to exterminate them with a devious, daring, somewhat farfetched scheme that will keep the audience guessing.

Spader’s performance as Ultron really stands out. Although not as fully realized as Tom Hiddleston’s Loki from the first Avengers movie, his portrayal is still very strong, with a quick wit, horrifying intentions, and an affinity for the song “I’ve Got No Strings” from Pinocchio. He is probably one of the top villains introduced so far in the MCU.

Hawkeye is another breakout star of the film. He delivers what are probably the best lines, and it wouldn’t surprise me if he plays a bigger part in the MCU going forward.

The action sequences also really stand out, especially the first one in the beginning of the movie. Harkening back to the final battle at the end of the first Avengers, it pans between characters, which is an approach that really shows how every member of the team, from The Hulk (Mark Ruffalo) to Captain America (Chris Evans) contribute in the battle.

The cinematography is also fantastic. The sprawling shots of landscapes and cities give a sense of scope to the film, and the camerawork in portraying certain parts are absolutely fantastic, giving an up-close and personal look at the Avengers.

The movie is not without flaws, however. Certain minor characters, such as Baron Von Strucker and Helen Cho, are not really explored, and you only hear their names once or twice before they play an important role in the plot. Some of the science in the movie is a little bit too far-fetched and not elaborated far enough, such as the science involved in the creation of Ultron,  and the introduction of a character in the movie’s third act needlessly complicates things. In addition, some action that happens off screen could have benefited from being shown on screen.

Despite these flaws, Avengers: Age of Ultron, is the rare sequel that actually outdoes the first film, and still effectively sets the stage for other sequels. It is a must-see this summer for any fan of action or superhero movies in general.

I would give it 4.5 stars out of 5.