So I've recently begun playing through TDM's fan missions, starting from the older ones and working my way up, and this is the first one that's really 'wowed' me... but it also outstayed its welcome. Fortunately, a lot of its objectives are optional, so you can condense the experience for yourself. I didn't want to, initially, but as more additional (optional) objectives kept getting added, my interest began to wane, especially some of the requirements of such. Don't let that put you off trying this, though - there's a lot of intrigue to be uncovered in this mansion, and between keyhunting and decent readables, you're given plenty of direction to not ever be stuck for long.