Before writing a review for this manga, I decided to backtrack and read the original "Ousama Game" story. Here's the thing, "Ousama Game" and "Ousama Game: Kigen" are essentially the same story just with different settings.
Now to be fair, "Ousama Game: Kigen" is a far better told version of "Ousama Game". I didn't care much for the original at all, but I was legitimately interested in the story of this one. All the problems with the original were fixed in this story. The cast is smaller and have better character development with their progression towards going insane and murdering each other done much better. Overall,
the characters behave more like human beings than they did in the original. The story is set in a remote village rather than a city, which makes the characters feel more isolated and helpless. The Ousama's orders build on each other very well, getting gradually harder to perform and having progressively more gruesome punishments. This story also has the police get involved with the events of the Ousama Game. I liked this because it made the story feel more realistic and, honestly, the detective was one of my favorite characters.
There are still a few problems with this story. While the character development and story flow are far superior to the original, there are still places where they could be done better. The reason for the Ousama Game and "big reveal" at the end are pretty lame. The reasoning behind everything is awfully far-fetched, and unlike some horror stories like Higurashi, there isn't enough background information or hints for a proper build up and reveal. This also makes it impossible for the audience to guess what's going on ahead of time, which can weaken the impact of the twist. In fact, the ending of this story makes the original story make even less sense. This works much better as a stand alone story than as a prequel to "Ousama Game".
Never the less, this one is worth a shot it you have some spare time on your hands. There are points that could have been better, but for the most part it was a decent enough read even if the end was a little disappointing.