Most murder mystery video games tend to be pretty silly. Maybe it's because, compared to mystery novels, they generally have a younger target audience, or because the visual element requires some extra pizazz, or some combination of the two along with some other things. While there are some novels that are out there, generally they're more restrained than video games.
But then we have a game like Missing Parts: The Detective Stories, which is about an ordinary guy, Magami Kyousuke, investigating ordinary murders in an ordinary city during his ordinary life. While there are some flavorful characters, there aren't any hyper-talented high schoolers or spirit mediums. These murders take place in apartments and alleys, not secluded islands or space stations.
And it's sooooo good.