In Black Box VR, your body is the game. Muscle groups map to elements — legs to water, arms to fire, and so on. The stronger a muscle group, the higher its elemental level. Opponents can strike back more effectively by targeting your weaker elements, so neglecting any part of your body costs you in the arena. Machine learning algorithms adapt the workout to push you toward balanced functional fitness, measuring progress and adjusting resistance so that every session is both optimal and genuinely hard. A VR fitness game where getting stronger is inseparable from playing.