I've been playing this masterpiece off and on for years now, always getting sucked back in by the masterful descriptions, the quaint English settings and sense of humour.
Its bastard hard, for me, but I love it anyway. One day I will finish this!
It starts off simply enough, but "escalates quickly" as they say into a swarm of puzzles and exploration of the old hall and surrounds. I love the way the author weaves in elements of the old family history into the houses history throughout the ages.