To assess effectiveness in serious games is the principal means for the purpose of developing the game and criteria for assessing quality of the game. Until now, serious games assessment has been implemented mainly through surveys that measured from the outside of the game using in-depth interviews, or sensor-based psycho-physiological observation. However, these methods have limitations that do not properly reflect on the gaming experience that is characterized by the coevolution through player participation activities. Therefore, we propose a model to assess the effectiveness of serious games systematically through evaluating the functionality based on the player's feedback.