So... the past twelve hours or so, they've been stuck in this puzzle:
Specifically, they haven't managed to step on the upper-leftmost arrow tile, taking them counterclockwise through the maze. For hours on end, they have been stuck trying to get around the wall in the upper right.
If they manage to get down that staircase, this awaits:
I guess it will only go slower and slower from here on, with trolls trying to go in the opposite direction just to screw with the progress. One mis-step will set them back by several hours.