There has been a long time project of Orange Bret, but it never finished, or is still in development.
He had a look at Wintermute, because he had concerns relating the handling of shadows on the pre-rendered backgrounds in Acknex.
There have been other adventure projects, I remember Meteor Mess 3D and one of the Joozey, it is available, at least as a demo in the Free Resources http://au.conitec.net/ , because it was an entry of a contest.