Imagine you have to inform programmers about the development of a new feature. For the first iteration, it is always better to think of a single use case.
We game designers think in systems. Some go so far as to say “Game design is system design”. A system means having actors in a relationship, creating a space of possibilities.
For a new feature, it’s best to think of a single path to implement first. Someone talks about MVP, a minimum viable product. I have always preferred the expression “prototype”.
Without losing sight of the vision, respect the steps necessary for its development. The first step is best to be on the direct path.