The Case of the Golden Idol is a mystery deduction game where each scenario requires filling in names, causes, and motives by clicking on clues. The game has a single consistent murder mystery across twelve scenarios spanning several generations of the same family.
What most players complete the game without fully appreciating: each scenario’s named individuals are also present in earlier scenarios as background figures. A character who is murdered in chapter six can be spotted as an unnamed background person in chapter three, their presence unremarked, their future unimportant at that point.
Color Gray Games built the family history to be retroactively populated: players who replayed earlier chapters after completing the full game found individuals they could now name, attending events whose significance they could now understand. The game rewards its own replay not with new content but with new comprehension of existing content.
The final scenario’s solution — assembling the full conspiracy’s architecture — requires names gathered across all twelve chapters. Players who had played carefully had the complete family tree already built.

200 hours in and I never caught this. The developers really reward obsessive players.
On my first run and now I have to go back and look for this. Worth the detour.