About 38 hours in and I think I've got 4 main quests to go. Saw someone say they did it all in 18 hours, with like 2/3 of the side quests. No idea how. I guess they didn't get lost in the castle as much as I did.
I'm at 2/3 of the challenges done. Feel like there's a boat load of stuff to do still. Having a real bitch of a time finding all the field guides and chests. It did finally dawn on me about 30 hours in the best way to find the field guides and I felt like a moron when it clicked.
Third trial was vastly different from the first two and pretty cool. Also exposed me to yet another new part of the castle.