Before we build anything we argue about how it holds up once the novelty wears off. Making a first session exciting is not the hard part. Making someone want the fifth one is where the design either works or it does not.
Most of that work is deciding what to leave out. A mechanic goes if it only looks good in a trailer. A system goes if it is there to take something from the player instead of handing them a decision. We would rather ship less and mean it.
We came to this from the other side of the screen, and we remember exactly how it feels when a studio stops respecting your time. That is the line we are trying not to cross.