Digital serious games and game-based learning have contributed to the expansion of new educational paradigms, where the use of computing resources is mixed with traditional ways of teaching. Allied to these advances, the virtual worlds are increasingly being used as tools to motivate students, providing immersion, autonomy and dynamism. This paper shows the development and application, focusing on the latter, of JASPION, a ubiquitous serious game integrated to OpenSim virtual world for computer networks education, which has an adventure narrative style with a storyline inspired in “The Fantastic JASPION” television series, placing the player in the role of a character. Topics of computer networks’ subject from Computer Science degree are contemplated. The ubiquitous features are contemplated by the sensitivity of cognitive style and level of expertise contexts, providing a customized game play profile for different players. The approach seeks to place the student on a transparent learning environment, reflecting aspects of ubiquitous learning, and is applied taking advantage of an assessment carried out by a hybrid method that explores two main instruments: adaptation of a questionnaire (Savi, 2011) and analysis of user’s interaction with the game through the computer screen capture. The results show the existence of motivational signs on students about computer networks discipline, highlighting the game’s potential as an educational tool.