The New Gamer has a fascinating video, with analysis, of the "averaged gameplay" of fifteen different gamers playing through level one of the classic shmup, Gradius. Why Gradius? Because it's "an auto-scrolling shoot'em up, is programmed so that the stage automatically scrolls at a fixed rate. With the stage constant, that allows us to compare how the player interacts with the AI and how, retroactively, the AI responds to that."
The resulting video (.mov), while providing unique insights into the design of the game, is unexpectedly dazzling to watch, as if Gradius has been reengineered as a light show with the ships dancing in concert.