I first played this VN in 2011, having read Accany's review of it (it was on his rather long list of recommended VNs), and at first, I had trouble getting into it. To be blunt, my distaste for mysteries is pretty much the biggest reason why I had trouble with this... but the protagonist is, in some ways, your typical 'stick his nose in everything and anything' detective, meaning that he frequently takes actions that make me want to face-palm. In addition, his unwillingness to put the puzzle pieces together (some parts of the setting come together indirectly really early on, and it always bothered me didn't figure it out then and there) bothered me as well. Nonetheless, I set that feeling aside and decided to replay this, since it is technically a classic VN, lol.
Kurenai no Tsuki is one of those rare VNs (rare even then) where all the characters are full adults with their own occupations and lives. It is also a combination murder mystery, fantasy, and horror story. The game's setting is an isolated village in the mountains, where the protagonist, Kouya accidentally stumbled onto the bathing scene of the two main heroines, Sunao and Hiori. Being old-fashioned Japanese women, they of course demand that he follow the rules and pick one of them (or both of them) to marry. If this VN were to have been made this year, then it would have turned into a series of moe antics, with good-hearted villagers blessing the potential marriage and the mystery being cleared up as something relatively innocent. However, Kurenai no Tsuki was made in 2009, when it was still normal to have this kind of beginning take a different track.
This story has a ridiculous number of choices, most of them you are required to pick eventually and the only thing you can pick is the order, which makes them useless choices in my mind. Objectively, this is perhaps the most negative point of the VN, lol.
There are two arcs to this VN, based on a choice made mid-way through the second chapter, which requires you to pick between Hiori and Sunao. Depending on which you choose, you get to look at a different side of the events and mystery of the story. There are four heroines, two of which are in each arc. The first one follows the villagers' side and contains Sunao's and Akari's paths. The second one follows a second faction and leads you to Hiori's and Kokoa's paths.
While I enjoyed this VN and liked its characters, the fact is that it doesn't really meet my tastes, even now. I love Sunao and Hiori, and so I always felt that this VN could have done without the mystery elements, since the protagonist is so paranoid he is willing to doubt those pure-hearted girls at the drop of a hat. That's probably my problem, since I was already thinking of those two as my waifu inside the first ten minutes of the VN each time I played it, hahaha...
Anyway, this VN's atmosphere is frequently gloomy and the villagers are insanely xenophobic (violently so at times), and the deaths that keep occurring only make things worse. Nonetheless, as a story it is very well-made and has a really interesting setting. Kokoa's scientific approach to the mystery of the village is also helpful, since it provides some perspective when you find yourself falling into baseless superstitious paranoia, haha.
I recommend this to fantasy mystery lovers, though don't expect that the mysteries will all be solved in a single path.
Edit: Oh, and the true path is the harem path, lol.