Serious games have emerged as a powerful tool for achieving targeted outcomes beyond entertainment, such as learning or raising awareness about a topic. Considering their pervasiveness and wide adoption in the educational domain, traditional assessment approaches of these games have predominantly focused on their entertainment value and achievement of learning objectives. This paper proposes a comprehensive evaluation framework that goes beyond traditional dimensions to include aspects relevant to empathy raising and attitude change. The proposed framework has been validated through three user studies, assessing entertainment, historical awareness, empathy raising, and attitude change for three games, involving in total 98 high school students. Results from the studies are presented, as well as implications and lessons learned regarding the overall methodological approach, the evaluation instruments used, and the procedures followed.