I figured I might as well try to route a speedrun for Nancy Drew: Secret of the Scarlet Hand while the game is semi-fresh in my mind.
The first part of the game is pretty easy to route, because Nancy is given a literal task list. You need to do everything on the task list, and talk to Taylor Sinclair at his office, in order to trigger the robbery scene. Triggering the "Henrik gets amnesia" scene is pretty simple, too. Just investigate the scarlet hand and learn about cinnabar. You can do that in under five minutes.
Once Henrik gets amnesia, routing the game becomes a nightmare, because you have multiple storylines to juggle, and if you do things in the wrong order, phone calls don't work. My last time around, Mr. Daddle refused to pick up the phone, ever. There's even a glitch, where if you wait too long to call Prudence Rutherford, you can't call her, ever. I'm sure there's an ideal order to do the storylines in, but I'm not sure if I have the patience to figure out what it is.