Theatre

The plot of the game is not exactly original - you have to enter an old theatre because you forgot something inside, and end up being trapped inside -, but the setting is really great : the horror is shown with little subtles touches, sounds, apparitions, and increases as the game progresses. The theatre is vast, with a lot of areas to discover or unlock, and as the game goes on those areas are more and more dark, empty and dangerous. The descriptions are well-written and coherent, which makes you really enter the game.
There's also some puzzles : they are fair and not really difficult, but not really easy either. I really liked the bits of paper you find in some places, which tell you another side of the story, and finally give some answers near the end (and are quite fun to collect). The implementation is very good and polished (I must say I didn't find any bug), and the parser provides quite a lot of responses. There isn't a lot of NPCs, but it's not important here because of the genre.
The game is quite long (more than two hours, at least), but I found the ending quite unsatisfactory : the author builded a nice and peculiar atmosphere in this theatre, but ends with a too classical (at least for me) theme (I won't say I don't like the theme, but the author could have carried on with an atmosphere of his own rather than going on with (Spoiler - click to show)a seen-before Lovecraftian style). Apart from that, it's a solid game, with a very good setting.