Just finished Danganronpa 2. Save file says it took me 31.5 hours and I feel it could easily have shaved off 8 hours without losing anything. Poor pacing is the biggest problem with the game, what with all the repetition, irritating mini-games and the mundane dialogs that go on forever. That said, it was still a decent game. Second half was more interesting than the first for sure. It had some really cool moments but then it also had these "only in video games" moments that balanced them out.
The tonal shift from the first game was kind of jarring as well. Danganronpa 1 had this oppressive atmosphere (of despair?) where the stakes felt higher and there was an urgency to complete the story. In comparison, this game occurs on a tropical paradise island and it has all sorts of jokes, double entendres and comical characters that kind of suppress the serious nature of the story they're trying to tell. I guess I'm in the (apparent) minority of players who think the first game was better than the second.
Also, Zero Escape is easily better than Danganronpa.