Horrible Dream is a psychological thriller from the first person. After walking through the dark alleys of an abandoned city, the main character feels that forgotten horrors are beginning to awaken from the depths. While exploring abandoned buildings, he unexpectedly encounters unexplained events and strange phenomena that make him wonder about the nature of reality. In this world of mysterious past and unexplored mysteries, the main character finds himself caught up in a whirlwind of events that go beyond his understanding. His search for the truth leads to the discovery of amazing facts, but also causes incomprehensible reactions from others. It soon becomes obvious that there is something unimaginable lurking around every corner of the city, and the main character realizes that his life will change forever after this journey in a world of riddles and mysteries