Hereby we present the first results of a Research Funded Project that focuses on the use of SG (Serious Games) with citizen’s participation in urban design projects. After the early trials of HMD devices used by the neighbors in three urban scenarios, the complexity of obtaining results was confirmed due to the system limitations and users’ mistrust in spite of the scenes realism. Therefore, a contingency plan was defined, with a strategic variation, participating in events and expositions with big audience; a monographic hall of the architecture professional environment and an international exposition focused on video games. We were able to validate SG usefulness by testing the new use of HMD (Head Mounted Display) in great public gatherings and also a new interaction methodology through touch screens joined with screenings of great size in a semi immersive environment. By this means the user designs and modifies the scene in third person, navigating through it with the help of a joystick or using HMD as an alternative. The result of the screening has proven to be robust and stable along the time, it is accessible to all types of users and very encouraging. With this installation and the participation of the citizens in our project has increase exponentially, allowing us to validate the agility of itself by having different people playing simultaneously with it and taking data by automatically taking screen captures.