I know that the main idea here is a choose your own quest type of game, but having just finished playing Hatoful Boyfriend all I can think about is Dating sims so I went with a romance game!
Player Experience: Love and Loss
Core Mechanic, CYOQ/Dating Sim
Theme: Relationships growing and changing over 5 years
Core game loop: Player is shown Text on what is happening in the world and given 2 choices on how to progress
Who is the player?
An average woman falling in love with a friend
What is the Setting?
Small hometown restaurant
What is the Threat?
Breaking your heart and hers
What is the goal?
To settle down together