Mobile games occupy more market share than PC and console titles combined, while the designers responsible for delighting billions with their app store offerings remain relatively overlooked by avid players and academic researchers alike. Marginalized game developers in particular find themselves struggling to survive in the mammoth mobile marketplace, but few studies have yet to address their unique experiences. In this paper we present the results from a participatory research project to: discover the challenges that women, people of color, LGBTQIA+, and disabled game creators face in the mobile space; and develop actionable methods for dismantling those barriers to meaningful participation in smartphone play design. After summarizing the three most prominent hurdles underrepresented developers contend with, we then lay out ten key insights about how those impediments can be overcome. The piece concludes with a dozen brief proposals for concrete programs to implement a more representative and welcoming mobile gaming environment, and a call to action for us all to take part in building that better world.