Dream or actual game?

Okay, this is from a long time ago, so I cannot remember if it was a dream or a strange game, and it has been bothering me, so I want to see if anyone knows if it was actually a game, or if it was just another of my weird dreams from a long time ago.

You are looking after your little sister, and she runs off to this big mansion. The mansion is full of butterflies that can talk, and you find out that the butterflies used to be people, but had been changed into butterflies by the mansion or something. You have to search the mansion, solving puzzles and what not, to find your sister, so that the two of you can escape before being transformed at midnight (or whatever hour), and the clock is always ticking. Pretty much wherever you go in the mansion, there is a clock ticking away.