Okay, without revealing any spoilers (besides the game's central mechanical conceit), I've been playing for a few hours and this is by far the most interesting Zero Escape game in terms of structure. I love the idea that the game reveals fragmented scenes to you, each of which depend on others, but due to the memory-erasing, you as a player are free to explore them context-free as each playable character. I'm sure my experience is very different from the next player's because I'm exploring the chart of fragments in a different order. I don't know what mechanical twists will emerge, but I like how this seems to break the visual novel convention of following a particular flow, saving at junction points, and exploring each branch in sequence.

The only downside to the game (personal, as I don't have a great memory of the convoluted storylines leading up to this one) is that there are returning characters with complicated backstories (some of which I never unlocked in the previous games.) I wish the game did a more thorough job by providing a character synopsis or revealing backstories more explicitly. I ended up reading summaries of the 999 and VLR plots from a wiki before feeling comfortable proceeding in the story. But otherwise, this is a pretty incredible game.

@thatdudeguy: It's pretty awesome. I'm having a lot of fun trying to guess when the fragments take place based on the info I get (and before it's put on the chart).

Story seems awesome so far. You can find some good youtube summaries online if you haven't found one yet. They def help with the specifics of what's going on.