One of the major challenges of video game design is to have appropriate difficulty levels for users in order to maximize the entertainment value of the game. Game players may lose interests if a game is either too easy or too difficult. This paper presents a novel methodology to improve user’s experience in computer games by automatically adjusting the level of the game difficulty. The difficulty level is computed from measurements of the facial physiology of the players at a distance. The measurements are based on the assumption that the players’ performance during the game-playing session alters blood flow in the supraorbital region, which is an indirect measurement of increased mental activities. This alters heat dissipation, which can be monitored in a contact-free manner through a thermal imaging-based stress monitoring and analysis system, known as StressCam. In this work, we investigated on two primary objectives: (1) the feasibility of utilizing the facial physiology in au...