The first trial version, consisting of only the first week, was released as part of the Hakurei Cleaning game jam on 1 October 2018.
The gameplay of Comatose Chaos is largely based on that of Violet Detector. However, there are some changes made to improve the experience of playing. Most notably, teleportation is now activated with a single press of the C key, rather than two presses of the shift key. The player can also change the camera's orientation, like in Double Spoiler, with the A key.
Following the events of Violet Detector, Sumireko Usami has entered a coma. Once again, the residents of the Dream World have begun to attack her with danmaku. Sumireko is still able to access her social media accounts while in a comatose state, and in an effort to keep in touch with reality, she decides to post her battle records on the Internet, not knowing when she will wake up.
Comatose Chaos features original compositions in the style of ZUN, as well as arrangements of his music from Violet Detector, Legacy of Lunatic Kingdom, and Dr. Latency's Freak Report, by Spectral Nexus and Aka Kyuketsuki.