It was heaps of fun! We both got really absorbed in it. I'd made the map the day before, off and on during the day and evening. Maybe 4-5 hours work.

See my comment on your post - but this would make for a great game-kit.

If you could come up with a flexible system for the fog-of-war and organize parts of the map to work with the areas they'd cover, then let parents/kids share/collaborate online or offline to make their own adventurers.

If this were a Kickstarter project I'd back it in a heart beat