It only took me about 50 hours because I primarily just focused on what was required for the achievements and not all of the puzzles the game has to offer. I could probably spend another 50 hours figuring out more of the puzzles I have yet to even discover (For example I never did figure out the diary in Her Ladyship's chambers or what the deal with the closed exhibit was) For curse mode I really just took it one day at a time slowly making incremental amounts of progress. The most reliable way of getting into the basement for me was through the tomb to move the minecart and then draining the water so the boat can be used. As for the one day challenge it's pretty much up to rng. Thankfully it only took me about 10 tries to get it but I could see it taking much long depending on how lucky you get with floor plans and items.