In this paper we present the design process and some interesting field t rial r esults of two d ifferent game applications, designed and developed in order to extend and motivate the community of mPASS. mPASS is an urban accessibility mapping system that allows citizens to collect reliable data about barriers and facilities via crowdsourcing and crowdsensing and it uses these data to calculate accessible paths. On the one hand mPASS needs to collect a sufficiently dense, detailed and trustworthy amount of data. On the other hand, the community interested in obtaining accessible paths is not big enough to reach the critical mass of information needed by the system in order to provide effective services. To overcome this problem, we investiga...