The pilot was promising and innovative, but the later episodes seem to be getting very formulaic, which is unfortunate.
Two primary challenges with it after watching four episodes:
1) there were 191 people on the flight, why is the NSA only focused on 20? Does that mean only 20 on the flight are having these 'visions' or are we supposed to forget the flight had more people than that? No explanation.
2) I understand they need to focus on the two main characters, but it'd be more interesting if they had some B stories on the others on the flight or their interactions with each other vs. just focusing on the female lead's issue with her old boyfriend (yes, we know he's not over her) or the guy's issue with his wife (yes, she's conflicted over her feelings with her new boyfriend). Boring.
Overall, the writers need to build more momentum on the innovative aspect of the show - why the plane disappeared/came back vs. trying to force-feed the audience these weekly crime-solving plots, with a dash of info on the entire premise of the show - the flight! Build the foundation of the show, then add the other dynamics incrementally, otherwise interest will be lost fast.