Age of Ultron starts off immediately throwing the Avengers back into the action in a sequence that looks more like a video game than a movie. We get some one-liners from every character here (accept Hulk and Hawkeye) reintroducing them to the audience, and then we meet a villain who's not important beyond the setup, he matters very briefly simply because he's in possession of a magical scepter the Avengers want for some reason or another (it will later be used to create another hero).
The movie continues at a breakneck pace, giving us two new kind-of supervillains, along with the evil robot the film is named for, Ultron. Ultron was programmed by Robert Downey Jr. and Mark Ruffalo to protect the world, but in a matter of seconds he’s download the internet and decides he’d rather destroy it, but first he’s going to start with destroying the Avengers. And the rest of the movie is the usual stuff. Buildings get destroyed, The Hulk gets mad and the team has to stop them, ext.
Everyone is mostly good here. There’s nothing wrong with any given actor’s performance. Everyone’s pretty serviceable, and that’s about how the whole movie feels. There’s nothing wrong with any of it per se, but there’s nothing here that feels very special either.