It is with an all-picture PDF which makes it impossible to search or extract. This greatly diminishes its value as gaming material. The adventure itself is a nice bread-and-butter-affair with murky characters and great maps. Adventure alone 8/10, the whole pdf only 6.5/10.

Complete review (German) here: http://tagschatten.blogspot.de/2017/03/the-sinister-tunnels-of-greenfield.html

Subtracting the cover and the OGL from the text leaves us with a pathetic nine and a half pages module. I have not yet read it, but not Hickmann and Niles working together at the height of their powers would be able to produce something worth almost a buck per virtual page. This is steeply priced, to put it kindly. Never ever from this publisher again.