Teaching soft skills in intelligent educational adventure games is challenging due to their qualitative and context-dependent nature. Furthermore, educational software focuses mainly on teaching hard skills, not soft skills. This paper introduces a Fuzzy Logic-based Cognitive Walkthrough (FLCW) method to assess how an intelligent educational adventure game fosters soft skills such as communication, teamwork, empathy, problem-solving, and interpersonal skills. A novel, intelligent educational adventure game designed to teach the programming language HTML along with various soft skills is presented in more detail. The soft skills are integrated into the game through various tasks and interactions with non-playable characters (NPCs). The FLCW assesses the degree of ten identified soft skills that each task requires. Fuzzy logic models the uncertainty and subjectivity that characterize soft skill assessment. Four experts participated in the assessment process. The results of the FLCW indicate the percentage of each skill that a user/player demonstrates during each task. This is crucial for the effective design of the educational game and for developing the user’s soft skills progress tracking process.