Serious games have to meet certain characteristics relating to gameplay and educational
content to be effective as educational tools. There are some models that evaluate these aspects, but
they usually lack a good balance between both ludic and learning requirements, and provide no guide
for the design of new games. This study develops the Gaming Educational Balanced (GEB) Model
which addresses these two limitations. GEB is based on the Mechanics, Dynamics and Aesthetics
framework and the Four Pillars of Educational Games theory. This model defines a metric to evaluate
serious games, which can also be followed to guide their subsequent development. This rubric
is tested with three indie serious games developed using different genres to raise awareness of
mental illnesses. This evaluation revealed two main issues: the three games returned good results for
gameplay, but the application of educational content was deficient, due in all likelihood to the lack of
expert educators participating in their development. A statistical and machine learning validation
of the results is also performed to ensure that the GEB metric features are clearly explained and the
players are able to evaluate them correctly. These results underline the usefulness of the new metric
tool for identifying game design strengths and weaknesses. Future works will apply this metric to
more serious games to further test its effectiveness and to guide the design of new serious games.
