This paper discusses four concepts, video games, constructivism, MVC architecture and user-modeling. The purpose is to use an educational paradigm that fosters the idea of learning by doing and to develop a system architecture that ties video games to a pedagogical intelligent software system for help and supervision. We consider Constructivism as defined by Von Glaserfeld [1] as the educational theory, this within a web based environment using the MVC architecture proposed by Reenskaug [2] to design, implement and test a set of games that teach geography and physical science at the grammar level. The system in enhanced with a user-modeling server designed by Paredes [3] to guide students in their learning quest. In order to make it readily available, the system is centralized and accessible through the web with continuous feedback. The interface is both pleasant and fast,, we have chosen a combination of software tools, based on Java [4] and Flash [5] technologies. The system developed has been tested in school in Morelos, Mexico. The results presented, although limited, are promising. They show that the students learned the concepts adequately using the system.