The 7th Guest
The 7th Guest is a horror-themed puzzle game developed by Trliobyte and published by Virgin in 1993 for DOS and later ported to CD-i, Macintosh, and Windows. You play a character in an old abandoned mansion who, by solving various puzzles, uncovers the story of an evil toy maker who somehow used his toys to murder children. The story is told though ghostly vignettes which often include clues to the puzzles.
My first experience with this game was at a friend's house shortly after it was released. He had bought the game, but his computer wasn't powerful enough to run it, so, when he ran the program, it just changed DOS prompt foreground color to dark blue, and began playing the intro music, but didn't advance. After his father upgraded his computer, he was able to play, and, by the time I came over again, he had already solved several of the puzzles. We weren't very good at the game, so he bought The Official Strategy Guide and we used it to get though many of the puzzles. However, there must have been a bug in the game because, even with the hint book helping us solve all the puzzles, we were never able to get into the attic. I later played the game in a Windows port, this time with the Internet to help me with the more difficult puzzles, and still failed to enter the attic. To this day, I have never been able to enter the attic!
I own the Windows port of this game, but haven't beaten it.