Escape Game: Escape from the Halloween Mansion

Ads are hint 1, 2, and the answer only. I saw the answer to a certain problem and complained, 'I can't see it!' It's good for killing time. It's been a while since I've only played 3D games. This adds a nice flavor. ↑What I left behind as the advance party. It was another good-flavored Halloween mansion. I've already forgotten the problem I complained about not being able to see, but I remember thinking, 'I don't get it even with the hint, and with the answer... Huh? This? I can't see it!'