BACKGROUND: A GAME WAS DEVELOPED USING VIRTUAL REALITY (VR) TECHNOLOGIES TO TEACH GRAPH THEORY IN A VISUAL, HANDS-ON WAY. AN ITERATIVE MODEL WAS DEVISED TO DESIGN, BUILD AND PILOT THE GAME. WITH VIRTUAL HANDS, LEARNERS WERE ABLE TO MANIPULATE GRAPHS IN AN IMMERSIVE ENVIRONMENT. THE GAME GUIDED THE LEARNER THROUGH THE GAME'S MECHANICS AND FUNDAMENTAL CONCEPTS OF GRAPH THEORY BEFORE PRESENTING REAL-WORLD EXAMPLES OF GRAPH THEORY AND PROGRESSIVELY MORE DIFFICULT CHALLENGES TO SOLVE. LEARNERS WERE ALSO PRESENTED WITH A DASHBOARD CONTAINING VISUALIZATIONS, SUCH AS PROGRESSION OF LEARNING (MAPPED TO BIGGS'S SOLO TAXONOMY), BADGES AND A LEADERBOARD. A STUDY WAS CARRIED OUT WITH THE PURPOSE OF: MEASURING THE EFFECTIVENESS OF THE GAME IN TEACHING GRAPH THEORY; MEASURING THE GAME'S SUCCESS FROM A UNIVERSAL DESIGN FOR LEARNING STANDPOINT; MEASURING HOW MOTIVATED LEARNERS WERE TO PLAY MORE GAMES LIKE IT; DISCOVERING STRATEGIES EMPLOYED BY LEARNERS IN AN IMMERSIVE VR ENVIRONMENT; ANALYSING GATHERED DATA TO GAIN INSIGHTS INTO HOW LEARNERS LEARNED AND SOLVED CHALLENGES. METHODS: A COMBINATION OF METHODS WERE USED IN THE STUDY OF LEARNERS (N=20) PLAYING THE GAME. OBSERVATIONAL NOTES WERE TAKEN WHILE WATCHING GAMEPLAY PROJECTED ON A LARGE SCREEN. A THINK ALOUD PROTOCOL WAS IN PLACE ALLOWING LEARNERS TO VERBALIZE THEIR THOUGHTS AS THEY PLAYED. DATA WAS AUTOMATICALLY GATHERED BY THE GAME ENGINE AND STORED FOR LATER ANALYSIS. A QUESTIONNAIRE WAS ADMINISTERED TO THE LEARNERS WITH SOME QUESTIONS MAPPED TO MODELS OF GAME-BASED LEARNING EVALUATION AND UNIVERSAL DESIGN FOR LEARNING. RESULTS: A SIGNIFICANT MAJORITY OF LEARNERS REPORTED THAT THE GAME IMPROVED THEIR UNDERSTANDING OF THE FUNDAMENTALS OF GRAPH THEORY, THAT THEIR INTEREST WAS STIMULATED IN PLAYING MORE GAMES LIKE IT, AND THAT IT WAS A QUICK WAY TO LEARN ABOUT GRAPH THEORY. THEY ALSO FOUND VISUALIZATIONS OF THEIR LEARNING (INCLUDING PROGRESSION) IN A DASHBOARD TO BE CLEAR, UNDERSTANDABLE AND USEFUL. THE GAME WAS SUCCESSFUL FROM A UNIVERSAL DESIGN PERSPECTIVE. SOME LEARNERS STATED ALOUD THAT THEY WERE VISUAL OR HANDS-ON LEARNERS AND THAT THE GAME SUITED THEIR WAY OF LEARNING. FURTHER DATA ANALYSIS AND VISUALIZATION REVEALED THAT IT WAS POSSIBLE TO IDENTIFY WHERE LEARNERS WERE ENGAGED WITH REAL-WORLD EXAMPLES AND WHERE LEARNERS RESORTED TO TRIAL AND ERROR TACTICS IN THE CHALLENGES. OBSERVATIONS ALSO REVEALED THAT LEARNERS, IN THE FREEDOM OF AN IMMERSIVE VR ENVIRONMENT, ENGAGED IN A RANGE OF DIFFERENT STRATEGIES WHILE SOLVING CHALLENGES. CONCLUSIONS: ONE OF THE PRINCIPLES OF THE UNIVERSAL DESIGN FOR LEARNING FRAMEWORK IS OFFERING CHOICE. WHEN A VR GAME IS OFFERED AS A CHOICE ALONGSIDE MORE TRADITIONAL MODES OF TEACHING, LEARNERS WILL RESPOND POSITIVELY, THOUGH CAREFUL DESIGN IS REQUIRED - THE DESIGN OF THE GAME INVOLVED A CAREFUL MAPPING OF LEARNING TO A TAXONOMY AND THE GAME GATHERED DATA THAT ALLOWED FOR VISUALIZATION OF LEARNER PROGRESSION. SIGNPOSTING OF LEARNING OBJECTIVES AND THEN SHOWING LEARNER PROGRESSION TOWARD THOSE OBJECTIVES, ALONG WITH IMMEDIATE FORMATIVE FEEDBACK, ARE AN EFFECTIVE WAY OF ENGAGING STUDENTS AND IMPROVING LEARNING OUTCOMES. LEARNER AUTONOMY CAN BE AIDED BY AN IMMERSIVE VR ENVIRONMENT, AS EVIDENCED BY THE DIFFERENT STRATEGIES BEING EMPLOYED BY DIFFERENT LEARNERS TO SOLVE CHALLENGES IN THE GAME.