This module is a relatively straightforward wilderness hexcrawl, with a fairly loose plot. It could be used as an open-world adventure, but the general level of quality and editing is below that of other modules of the time (let alone modern efforts). It's labeled for characters of levels "4-10" which is quite a wide range and likely level 4 characters wouldn't survive - the pre-generated characters are levels 6-7. Still, it is interesting to read and might be usable with a little extra work on the DM's part to introduce some roleplaying and give the encounters more "character" when used.
I liked the variety of different encounters in the many areas. I disliked how this was more similar to a campaign framework than a fast or medium paced adventure. For instance, the players background starts them over 500 miles from the coast they need to explore and the goals aren't very concrete besides "Get gold and map the area."
There are no NPCs of note in the "adventure" so you have to create your own.
The treasure makes no sense. Barrels of gold nuggets worth 200gp for instance, but 50,000gp for each character upon returning to civilization with a map.