This paper explains details of a creative writing project aimed at increasing students' motivation to write in English and develop collaboration skills. Forty-eight first-year -- A2-B1 Common European Framework of Reference for Languages (CEFR) level -- English as a Foreign Language (EFL) learners enrolled in a reading and writing course at a Japanese university and participated in a collaborative, project-based language learning task. In small groups, students created gamebooks (approx. 1,500 words) in the Choose Your Own Adventure (CYOA) style using Google Slides. Both experiences from class and survey results suggest that students found the activity highly enjoyable and that their motivation to write in English increased. In the survey, many students also commented about the positive impact that this project had on their ability to express themselves in English while collaborating with their classmates, suggesting that the project fulfilled its two aims. [For the complete volume, "CALL for Widening Participation: Short Papers from EUROCALL 2020 (28th, Online, August 20-21, 2020)," see ED610330.]