Disney's Frozen was the biggest animated movie that had ever come out when it was released. It's the sort of movie that would have spawned an automatic sequel were it any other film. But Disney doesn't always make sequels to its animated projects. In the case of Frozen however, they made an exception, and Frozen II took over the top spot as the highest grossing animated film ever. While the second movie brought back familiar characters, it changed a great deal, and Kristen Bell thinks one particular aspect of that change, the way the story matured, was a big success.
While both Frozen movies are certainly suitable for the whole family, the tone of Frozen II was considerably different than the first movie, and the voice of Anna, Kristen Bell, recently told Self that the more mature elements were something she's quite proud of. Bell compares Frozen II to the most recent season of Veronica Mars, where the actress also feels the story was necessarily matured. According to the actress...
There’s only so long you can play out a love affair…and let me tell you, people were angry that we killed Logan. I’m still proud of the way that we did it. I thought we matured it. Same thing with Frozen II.
Kristen Bell is certainly right that the most recent season of Veronica Mars was controversial. The season ended on the death of a fan favorite character, and a lot of fans were not happy about that decision, but Bell clearly thinks it was the right decision, to take the character, who was much older than the character fans were first introduced to, and mature the story alongside the character.
Not nearly as much time passed between the two Frozen movies, but Kristen Bell thinks the maturing of the story was equally necessary, and equally successful. And Frozen II certainly did deal with some serious themes. Kristen Bell specifically talked about how her own struggles with depression informed her character and Anna's relationship with Elsa. It wasn't so bleak as to upset small children, but at the same time, when those children grow up they'll likely see the movie in a very different light.
Frozen II isn't a perfect movie, whether it's even a "better" film than the first one is certainly a topic of debate. Having said that, the emotional journey that several of the characters go on, not just Anna but Elsa, Kristoff, and even Olaf, is certainly more mature than the first movie. It allows Frozen II to stand on its own and not simply another adventure with the characters from the first movie, it gives the sequel a reason to exist. The only question now is that whether there's any place else that Anna, or Veronica Mars, have left to go.