Here is my game idea. The email game. The game would look totally like an email app you use daily. You receive and send in-game emails, interacting with varios characters, trying to unravel a conspiracy.
Like real emails, you will receive ConMails in real time, the icon can also have notification badges and new mail counters just like real mail apps.
In game you can also contact other players to exchange thoughts or get help solving a particular riddle (some “real players” can be developers’ agents, allowing to manage difficulty and pace of the game).
You can interact with emails choosing from a list of predefined responses.
During the key plot moments, you might be able to send real typed messages and get answers from the real people (developers) to make the experience even more immersive.
It is possible to use a “season” system, competitions, rankings…
I would play this.