The plot: You show up to visit your old friend John, but he's nowhere to be found; you get trapped in his house by a snowstorm; there seems to be some kind of crazy tunnel in his basement. Adventure ensues. A goblin, a demon, a devil; color-coded rooms.
The puzzles are good overall. A couple of them have particularly nice twists; a couple, on the other hand, seem a bit random, but the game is small enough that even the random ones can be solved by experimentation and you don't have to go too crazy.
What's mostly lacking is atmosphere. I don't think I formed a really vivid image of any location or object in the game. Everything is described minimally, and the only objects implemented are those necessary for the puzzles. At the beginning the protagonist does have a nice humorous voice as he talks about John and his habits, but that too goes away once you get underground.
If you're looking for a decent demon-puzzle or two and don't want to be bothered with the rest, go for it.