Recent studies of transmedia storytelling have focused on the nonfiction genre in investigating how literature and historical materials are transformed into interactive narratives. This study used the example of Henry David Thoreau’s Walden and its video game adaptation by Tracy Fullerton (Walden, a game) to analyze transmedia storytelling strategies. Walden, a game enables players to experience the life described in the original text, such as simulations of the facts that Thoreau build his cottage and collected berries. Furthermore, the game demonstrates how nature writing can be visualized and “audiolized.” Fullerton calculated the frequency of the species appearing in the text and combined this with her personal experience in visiting Walden Pond to present a historically and textually accurate natural environment for players to explore. Adapting nonfiction into video games requires in-depth research to accurately represent the original work and historical context. Fullerton achieves this in Walden, a game and thereby creates a beautiful, slow gaming experience.