It's very different, from say XIII or normal FF; the plot is uncovered at the rate that you decide to uncover it. I personally didn't think the no-closure ending was a bad thing. If there is something unique about XIII-2's story does well is that it does not have a clear narrative flow, which might seem initially bad for a series known for explosive narrative but I enjoy when a story does something to shake up the typical foundations. In a story about time travel and alternate universes, it seems to dovetail well.

In other words, this game does have a different "storytelling structure" to begin with from XIII. To clear up the image. Exploring that is kind of the entire point of the game. You're traveling and dealing with parallel universes. Which one of these threads is the "true" history or the proper way things should go is a fairly big theme in the game.