Cosmo Explorers is a project aimed at developing novel and different strategies in formal education context (11-18 years old students) using videogames for educational purposes. Teachers encourage students to play with a videogame in the classroom to learn not only STEM, but also soft skills and teamwork attitude while having fun. The core of Cosmo Explorers is a competition for the creation of the best space exploration program using the videogame Kerbal Space program (KSP). KSP is a space flight simulator that allows the player to experiment with the construction of rockets, satellites, spacecraft and rovers, send them into orbit or undertake long interplanetary journeys taking into account gravity, thrust of the engines, fuel availability, energy supply, aerodynamics and much more. The flexible and modular nature of the project allows each teacher to fine-tune the activities according to their needs, moving from skills development (such as management of group work, solution of complex problems, management of medium-long term projects, learning from mistakes, ability to forecast, risk assessment and decision making, digital skills) through educational contents (kinematics and forces, gravitation, celestial mechanics, technology, economy). The project (granted by the Italian Education and Research Ministry MIUR) was led by Infini.to - Planetarium of Turin with the National Institute for Astrophysics (INAF) and ALTEC (Aerospace Logistics Technology Engineering Company). It had a duration of 24 months and involved several teams for a total of more than 100 teachers and 1.000 students all over Italy.