*Contains spoilers*
I am a huge fan of the first movie, I've watched it more times than I can count, memorized all the songs, and even the whole movie. The second movie was such a letdown. The animations were amazing, too good for a mediocre plot. I am no expert, these are just my opinions right after the movie that I may add onto later.
The Soundtrack is great. But the plot was terrible. Everything felt so rushed, like a bunch of episodes shoved into a condensed movie. Elsa was the central character who was on a journey of self-discovery. Anna, on the other hand, was this character that was very clingy towards Elsa and rather.. annoying. We barely got to discover her views as a character, sure she had personal songs, but were they strongly portrayed in the movie? No. The movie felt so rushed. It kept bringing up scenes from the previous movie, even Olaf summarized the whole thing. Sure, it was funny, but that just goes to show how much the second movie is lacking in the plot. This movie ruined the nice ending of the first movie. The voice acting didn't seem as good as the first. Whatever happened to the conflict between the tribe and the group of soldiers trapped in the forest? They resolved their conflict so fast although they had been fighting all those years. Where were their emotions and reaction when they finally saw the forest for the first time? Imagine the movie without having met the people in the forest, and the plot wouldn't have been affected. Kristoff didn't even have much in the movie either, other than propose to Anna, which brought no emotion on the viewing audience whatsoever. The movie also relied on Olaf's personality a lot. That of course, was used in the effect of the younger audience, who are the primary target of the movie. The previous movie focused a lot on the journey of the 4 central characters: Elsa, Anna, Kristoff, and Olaf (Sven too but not really a trivial part in the concept of character development), they barely evaluated two of these characters, Anna and Kristoff felt like there was just there. I feel like the first movie also relied heavily on the bond created between Elsa and Anna, and I just didn't feel that connection in the movie. Also, Anna just happened to get back with Kristoff and the others that fast without getting lost?
The movie felt like a draft, an unfinished project. It was mostly fan service, like Star Wars. "The storyline overall feels forced and clunky." - Sameen Amer
The quote pretty much sums it up.