Hey, sorry to hear you only got that far. It's not clearly stated in the game but after making a flag, you -have- to interview -two- people. These two people differ based on what kind of flag you chose to make. NPC interactions with all non-interviewable people are disabled during that time. If you'd gone around and talked to everyone, you'd have eventually found someone who wanted to do an interview about the flag (the only possibilities are for it to be Jack, Captain Frogsword or Hearthorn, the other NPCs don't do flag interviews)
If you do get further in the game, it basically 'ends' after the mutiny interviews, there'll be nothing left to do. The whole point was originally that one could craft a documentary by choosing their own path, and then view an actual documentary at the end of the game based on your decisions.
But thank you so much for playing and leaving a nice comment :) It's much appreciated!