It was the Director's Cut that I played, which kind of makes the problems worse. That extra part you mentioned is actually a sequel to what happened in the game, a reporter heard about something relating to the house(I forget what exactly) so he comes to the house to examine it. It's about 10 minutes long and you just travel through the house again(on rails) which is in even worse shape, and you discover the "monster" who lives there, and someone fights him off as you escape(I forget who showed up, maybe the doctor?). Of course the look of the monster changes from the original game so this sequel doesn't feel right, not that these points looked right the first time anyway. A lot of these fully 3D games look pretty terrible just a few years later.

No offense if you really did enjoy the game, I just couldn't get into it including the atmosphere, and I played it after midnight as that's about the only time I really have to play long games. At least the Director's Cut included an alternate ending for the first game, one that is pretty much better than the original.

I know of another mediocre game, Sherlock Holmes: Mystery of the Mummy. I played the DS port but everything about it is terrible. The puzzles feel out of place, like the developers tried to think up good puzzles first and just wrapped the game around them. Several of the puzzles are pretty stupid too. And the story makes no sense, almost like a Scooby Doo mystery but meant to be taken seriously. There are playthroughs on youtube if you just want to experience it.

I'm glad someone mentioned the Broken Sword games, I've played the first one and enjoyed it. I have most of the later ones too but haven't got around to them yet. There's also Toonstruck, it's a title I haven't seen mentioned yet in this thread. And the Discworld games, most Simon the Sorcerer games, and The Neverhood. These are just PC games, several good adventure games were released on the Nintendo DS as well. Trace Memory/Another Code, Hotel Dusk, Ghost Trick, etc.