Looks very ambitious.
EDIT: It's SERIOUSLY ambitious. With the possible exception of "Finals at the Academy" I can't think of any FM that has more collectibles in it than this one.
There's a tragic backstory behind the manor, and that is detailed in a 13-part tome, of which the pages are scattered through the mansion (I'm currently only missing the tenth one).
There's also a lock that requires four keys. Each of those four keys corresponds to a card suit, and to get each key, you must... wait for it... collect every card of the suit from Ace to King. Toss in all the keys and it's 70 items to collect in total. Fortunately there are in-game clues to help you find the cards... except I'm missing two: The King of Diamonds and the Eight of Spades.
Does this mean that I'm tired and bothered by hunting down cards? TAFF NO. This FM is the most detailed, thought-out, realistic manor heist-affair I've seen in years. The manor is large and comes with a detailed map, there's plenty to read, marble is used sparingly (light is a bigger overall concern) and it's an absolute joy to play.
And here's the best part: It has random elements, determined at the start of the game by the looks of it. This FM is a whodunit that mixes Cluedo and Thief. In my playthrough poor Duncan was poisoned at dinner, and I had to look up poison symptoms in the library to learn which poison killed him, and then which patron had a batch of it lying around, to finger a suspect. Alternate methods I've seen include stabbings, bludgeonings and poisoning via alcohol. Did I mention Garrett gets to pick one of four (five?) different points of entry into the manor? This one has replay value, which is rare for a Thief FM.
nicked If this had been part of the 20th Anniversary Contest you would have nailed the top spot! I'm in the home stretch of it, but I'll be very surprised if this doesn't score a full house of points just like "Lost Among the Forsaken" and "The Unbidden Guest".