The Danganronpa-like elements aren't nearly as prevalent as the marketing might have made them out to be. It's an interesting enough mechanic, and it's cool how it forces you to use different characters and strategies for each playthrough, but it's ultimately fairly minor. As cool as it sounded, I never felt like it had a big impact on the gameplay.
EDIT: As for the story itself, well, it's not particularly great, and while the characters are allowed to show some depth in their personal quests, the random traitor mechanic forces each of them to be interchangeable, which is pretty disappointing since I ended up liking most of them. The main plot has the problem of needing the secret files from NG+ to explain everything going on, but I will say that its that brand of big, weird sci-fi that anime does well, and I liked it well enough.