Although Miles brought his friends to the island to solve a murder mystery, the fictional story actually maps out a lot of what happens in the film.
First off, Miles has a packet of fake blood in his shirt to simulate being killed, which mirrors the hot sauce packet Benoit uses later on to make it look like Helen was shot on the stairs.
Second, the solution to the "murder" is actually very simple, but it's filled with nonsensical layers to confuse the guests (and the audience).
Third, the answer to the mystery is hidden in plain sight. While the necklace containing the diamond is right in front of them during the meal, the napkin with the plans for the company is in Miles' office, hidden behind the false napkin.
And finally, Miles took credit for something he didn't create. He introduces the game by saying that he spent a lot of time crafting the plot, but later confesses that someone else wrote the whole thing. It's exactly how he took credit for Andi's hard work building Alpha and then stole the company out from under her.
Basically, Miles has no originality whatsoever.