One of the best visual novels you could read. There is 2 games : 9 hours 9 persons 9 doors, and Virtue's Last Reward (the third game of the trilogy is Zero Time Dilemma).

The creepy atmosphere in both games is just perfect. That was the first visual novel i readed, and he's still the best to my eyes.
Story, music, characters, atmosphere, everything is gathered to tell the best story i've ever seen.
Also, 3D used in VLR can be surprising but we don't mind it after a couple hours.

The escape room sequences can be a little tricky sometimes, but it's worth it.

At least, try this masterpiece.