Great game, had that soundtrack in my head for weeks. It's great that you actually need to think through things and look for subtle clues, and make real deductions.

A man of few words, in fact, his suit has more to say.

In my opinion, Artstyle. A game with a great artstyle holds up much better with time than one going for just good graphics. For example, I still think Curse of Monkey Island looks great, and that was released in 1997.