The game fenestra involves guiding an old man through puzzles by having him travel between two worlds - a dark modern city and a bright outdoor setting - whenever he dies. Players must use objects and layouts in both worlds to reach the exit door of each level. Puzzles may involve choosing where to die, pushing boxes, activating buttons and switches, carrying keys between worlds, and timing deaths with events. The overarching goal is to progress the story of the protagonist by beating levels, with the challenge being to figure out the tasks needed to access each exit.