CALLUS is a short psychological horror game in the walking simulator genre, focusing on spatial exploration and the perception of detail. The player returns to a familiar apartment, where the furnishings remain the same, but the feeling of safety is absent. The length makes the experience condensed and concentrated. Space, attention and perception The main emphasis is on slow movement and observation of the surroundings. The apartment serves not simply as a location but as a vehicle for meaning, where every object and angle can alter the perception of what's happening. The game doesn't lead the player by the hand or highlight important elements, leaving interpretation to the player. Tension is generated through silence, the rhythm of footsteps, and visual accents. The absence of familiar horror mechanics heightens the discomfort, forcing players to peer into the space and notice what would normally be ignored. The final effect depends on the player's attention and willingness to perceive hidden meanings. Features of the game A psychological horror game in a walking simulator format. Short duration, about 30 minutes. Realistic presentation without game conventions. Lack of use of AI.