I thought it was a solidly made film and had its moments, but overall was pretty mediocre, and in trying to recapture the same story and character points from the first film, it ends up being much less than it could have been.
Emily Blunt is a very good actress, and I liked a lot of her take on Mary. They didn't really do much of anything with Mary Poppins as a character, which could have set this film apart from the previous one. She's still just sort of a force of nature in the children's lives who is there to occassionally sing an instructive song.
Michael is just sort of a static, generic character, and there's nowhere interesting for him to go. He's useless without his wife and he's forgotten how to be a kid. Okay. Where have we seen that before?
I'm not sure what they were doing with Jane.
I think this was a misstep for Lin Manuel Miranda. He's a heck of a composer/lyricist, but he's not super talented as an actor or a singer. He's succeeded on Broadway because he's positioned himself to succeed, but he disappeared in this cast, even with moments designed to spotlight him. A lot of his stuff just felt perfunctory. He should have done less of his shtick, and something new. Trying to be "another Bert" with no really compelling connection to that character was a mistake. And all the film's mistakes flowed from that reliance on nostalgia. The filmmakers seem to misunderstand what made certain elements of the original so good to begin with.
For instance, "Spoonful of Sugar" doesn't work because of the influx of magic into the children's lives...it works because of the influx of magic on an intimate scale. It's scratching the surface of what Mary Poppins can do, and where we can go. When you dive into a CGI waterworld chock full of magic in her introductory sequence, there's really nowhere to go from there.
"Step in Time" didn't work just because it was a big choregraphed musical number. It worked because it was a big musical number on the expansive rooftops of London where the chimney sweeps risked their lives rather recklessly to express their joy. And there's a dash of magic to it. And other people saw it happening and reacted to it. A relatively contained wannabe number like "Trip the Light" simply doesn't have the charm, the energy, or the interesting choreography to compete.
I think the movie just needed a bit more thought and effort put into making it into its own animal.