Dad thought it was going to be a silly comedy, but it's actually a drama. A sad one at that! But, oh-so good! He really liked it, but said watching Tom Hanks made him think Forrest Gump. He looks nothing like Forrest Gump anymore. That's his mental hang-up.
The trailer below has more of the lighter-hearted moments. The movie is actually two-fold. One aspect of the story is about Walt Disney trying to convince the author of Mary Poppins, Mrs. Travers, to sign over the rights to make her books into a movie. She's very stubborn and is afraid of the spectacle he might turn her story into (NO ANIMATION!).
The other half of the movie is a series of memories as to why Mary Poppins (never just Mary) is so close to Mrs. Travers heart--why Mary is family. Very serious. The movie is PG-13 mainly because of this part.