(Semi-cross-posting this here if people haven’t seen it on the intfiction.org forum.)
A new user recently discovered partial source code for a previously-unknown version of ADVENT, called “ADVENTP”: a 500-point version written in Pascal by George Richmond and Mike Preston. Unfortunately the datafile which contained the text and much of the puzzle logic is missing; he’s contacting Preston about that, but it’s uncertain if anything will come of that. [EDIT: The comments date this version to March 1979.]
He mentioned that the new puzzles in this version included “a wolf, a guard post, the requirement that you build a bridge and a ladder to get certain places”; the source code also indicates that one point would be awarded per room visited, to force people to explore the mazes. I’m only closely familiar with Crowther and Woods’ original 350-point version, so none of those sound familiar. But does anyone else recognize those puzzles? Did they survive in another version of the game?