Hidden Agenda is a detective mystery thriller following two protagonists; Becky Marney, a police officer who after capturing the infamous Trapper serial killer gets promoted to a homicide detective, and Felicity Graves, district attorney who convicted the Trapper. Five years have passed since Finn was caught and accused of the series murders, and his admitting to crimes didn't play in his favor. Finn is about to be executed in a couple of days and Felicity goes in for a talk with him only to find herself questioning if he is the real killer.
The story now takes turn based entirely on player's choices, it may lead you to believe that Finn really is the killer, or that he was protecting the real killer, or even the player may end up being a primary suspect in the killings. The game is played entirely via smartphone app and requires both PS4 device and your smartphone to be on the same wi-fi network. Upon starting the PS4 game, the smartphone app will be able to join and the player gets to select his name and color which is mostly used to distinguish multiple players when playing competitive mode where each of the players have his/her own hidden agenda to achieve or prevent other players from achieving.
The story mode is most suitable for single player who can determine the narration of the entire game by making choices for the two protagonists. Game is paused and resumed via smartphone app only, and as the story progresses new characters, ripple effects, and plot progress get marked which can be checked on the smartphone app. Interaction with the game story is done in several different ways, depending on the scene in question. Most common is the choice you determine for your character, whether it is an action to perform or the way you wish Becky or Felicity to answer to a question being asked. Clue searching scenes prompt you to find 3 on-screen clues within the allotted time which affects story that follows, and quick-time events which are seldom, prompt the player to quickly drag the cursor to a point of interest to make the character pass unobstructed (i.e. not to stumble on a crate while chasing a suspect). And last, the player is sometimes able to shoot at the character on the screen. Doing nothing in either of the interactions or prompted choices is also an option and depending on the situation may even be a good choice.
Key choices in the game that affect the story in big way are called ripple effects and are marked on the smartphone app. In general, whenever the plot changes, new character info is uncovered, or ripple effect activated, the smartphone app will add it to the logbook for the players to check at any point during gameplay, whether the game is paused or not. The story is split into 3 chapters overall and between each of the chapters all the ripple effects that will affect further story are displayed.