Serious games have a great potential for training and educating people in novel and engaging ways. However, little empirical research has been done on the effectiveness of serious games, and although early findings do point to a moderately positive direction, even less is known about why some games succeed in effectively educating while others do not. We therefore propose a serious game, "COgnition-based DEsign Rules Enhancing Decisionmaking TRaining In A Game Environment (Code Red: Triage)", which is designed to empirically test a number of cognition-based design guidelines in the context of crisis management training that ameliorate mental model construction. Our purpose is to come to a set of design guidelines through empirical experiments that enhance the instructional design of serious games and can be used in the development of future games. Furthermore a method is discussed to extract the mental structure players have built during gameplay.