Mobile game applications stand as a profitable market, being mostly represented by independent startups striving to overcome their lack of experience. One of their big challenges refers to the adoption of mobile games by older adults. Appropriated methods for usability, accessibility and user experience (UX) evaluation of such domain remains a few in the literature. Engineering methods are still required for startup companies to overcome the challenge. In this paper, we sought to build evaluation methods for the context of startups, mobile games and older adults. This study is an empirical research based on techniques from the constructivist grounded theory methodology. Our findings show a lean framework aiming to guide startup practitioners to diagnose usability, accessibility and UX issues from tests of mobile games with older adults. We also provide a guide to usability and accessibility heuristics that can be employed to inspect the domain.