How do you measure "Timing"?

[The Crimson Binome]

What sort of complex movement are you going for here? If you make the obstacle course too complicated, the PC's will just work around it.

That happened in a recent game I was running. I described the room, the door on the far side, and the seven moving platforms which could eventually lead them from point A to point B. As soon as I mentioned that some of the platforms disappeared spontaneously, though, the group unanimously decided to go some other way.