I like this concept.
It would require [b]A LOT[/b] of work from the GM's.
Recording everyone's location, answering the left/right turns. 
Dealing with the monsters/traps and changing scenery.

I feel the map should be known only by the GM's.
It would need a good legend and clever challenges.

That's the type of game I'm imagining and would like to play anyway ;)