Soul Trapper is an audio adventure that draws from the history of radio mystery dramas and the nostalgia of choose-your-own-adventure games. This is the first episode in a series that relies on voice actor performance and stereo sound design, rather than a visual interface, as the primary means of "display" for the game world. It is a science fiction mystery adventure title centered around the player character Kane Price, a psychic investigator specializing in solving problems of a supernatural nature in the present day Los Angeles area. The game mixes exploration and puzzle play with a narrative that lasts around three hours. In this first episode, Ollie Ollie Oxen Free!, Kane Price and his associates chase ghosts, avoid the law, battle demons and solve a mystery surrounding a lost boy named Ollie. The game has visuals, but these are largely static and the next action is selected based on a number of options presented on the screen. At the bottom of the screen a map can be opened to get an overview of the different locations.