This is the Zodiac Speaking is a murder mystery game based on the actual Zodiac Killer case. The game does have some factual basis but is mostly a reimagining of what happened. The game follows around Robert Hartnell, a journalist hot on the tail of the Zodiac Killer.
As Hartnell develops an obsession for the Zodiac Killer, he becomes more and more haunted by vivid dreams of the Zodiac Killer and his victims. Through the help of his psychiatrist, he enters vivid dreamscapes that reconstruct the crime scenes, in order to help him solve the case and move on.
It is in these dreamscapes, that most of the game takes place. In there is an interesting blend of light puzzle solving reminiscent of point and click adventure games as well as a heavy emphasis on stealth due to the ever constant presence of the Zodiac Killer stalking you. The stealth is optional though, so people can turn if off before starting a new game in order to focus on solving the mystery uninterrupted. I would recommend trying it out for the first playthrough because the need to explore and solve puzzles while avoiding the Zodiac Killer creates a sense of tension that permeates the entire game.
Overall, This is the Zodiac Speaking is a pretty enjoyable and immersive experience, although flawed. The artwork, sound design, and gameplay work well together for the most part. The stealth mechanics are pretty unique in that the Zodiac Killer has set patrol patterns but will always follow you around, never leaving you with room to breathe unless you know what you’re doing. The game does have some flaws though. The voice acting for the Zodiac is not the best and undermines the immersion one may have in the game. The writing, for a murder mystery, is fairly weak as well, although still engaging.