"Imitation is the sincerest form of flattery." (Charles Caleb Colton)
Fan-fiction have always been a part of mystery fiction, I guess. I'm still surprised at the amount of Holmes pastiches released over the (many, many) years and on the blog, I've discussed a number of pastiches and parodies of various series. Of course, the quality of fan-fiction is not always even, with some very good, with some bad, but I do find it interesting that people enjoy certain worlds and characters so much they want to do something with all of that themselves.
Kamaitachi no Yoru game. In the original game, a group of people were trapped in the ski lodge Spur during a snowstorm, together with a cut-up body and a vicious murderer among them. Rengoku is set exactly one year after the first game. A wedding between two of the survivors of the first game brings the old cast together and after the ceremony, all of them go to the lodge again to continue the celebrations. Happy thoughts soon turn into fiery thoughts however when one of them burns to death in a room. It is unclear whether it was suicide or murder, but if the player doesn't act soon, more and more victims will turn to ashes...
Rengoku - Kamaitachi no Yoru 2 Another is playable on the PC (available here) and was written as a direct sequel to the original Kamaitachi no Yoru by three fans (note that there is also an official sequel, which is quite different from the fangame). Like the original game, Rengoku is a sound novel game: text is projected on a background accompanied by music and soundeffects, and you 'read' the story like you'd read a novel. At set points, you'll have to make choices, which will change the flow of the story (basically a Choose Your Own Adventure). In Rengoku, you'll be trying to deduce the true nature of the death-in-flames, and figure out who is behind the whole event.
For a free game, I enjoyed Rengoku more than I had thought I would. It's relatively short, but there are more than ten different endings available, most of them with you dying because you didn't manage to solve the case in time. Like in the original Kamaitachi no Yoru, it's actually possible to solve the crime at different points in the story, which can lead to fewer victims (this concept was dropped in the official sequels). The longer you take to solve the murder (not actual clock-time, but in terms of story developments), the more the story moves into horror-territory, with more victims bursting into flames until everyone disappears in a blaze. So you better make sure you find the truth in time!
Rengoku however is difficult to look at separate from the original Kamaitachi no Yoru: save for one new character, the characters and setting are exactly the same as the first game. Even the music is 'borrowed'. The mystery plot is also rather similar to the original game: okay, in this game everyone burns to a crisp if you're not in time (hence the title Purgatory), while the original games had everyone getting cut and stabbed (for the kamaitachi motif), but the truth behind the first death is actually extremely similar to that of the original game. In that sense, Rengoku is less of a sequel, rather than an alternate version of the original game. In this sense, you could consider Rengoku a rather predictable piece of fan-fiction. Also note that Rengoku contains spoilers for the first game (about the murderer and the trick used), so be sure to play Kamaitachi no Yoru first.
As a short piece of fan-fiction, Rengoku - Kamaitachi no Yoru 2 Another is fairly enjoyable. It definitely plays and reads like a Kamaitachi no Yoru game and for a free game, there's a fair amount of content available. The whole game however is perhaps a bit too similar to the original Kamaitachi no Yoru, including the mystery plot, so it might give you a feeling of déjà vu. But this was certainly not a bad way to pass the time. Rengoku - Kamaitachi no Yoru 2 Another is available for free from this site)
Original Japanese title(s): Varitra、Quiet、キリン 『煉獄 -かまいたちの夜２ another』