Background: Mobile technology is increasingly important for delivering public health interventions to remote populations. This research study developed, piloted, and assessed a serious game for mobile devices that teaches geohazard, maternal, and neonatal health messages. This unique mHealth intervention aimed at low-literacy audiences in low resource settings is part of the Maternal and Neonatal Technologies in Rural Areas (MANTRA) project: Increasing maternal and child health resilience before, during, and after disasters using mobile technology in Nepal. Methods: The serious game was developed through a co-creation process between London and Kathmandu based researchers by email and video-calling, and face-to-face with local stakeholders in Nepal. The process identified core needs, developed appropriate pictograms and mechanics, and tailored the pilot serious game to the local cultural context. Evaluations and feedback from end users took place in rural villages and suburban Kathmandu in Province Three. Field evaluation sessions used mixed methods. Researchers observed game play and held focus group discussions to elicit qualitative feedback and understand engagement, motivation, and usability, and conducted a paired pre-and post-game knowledge assessment. Results: The MANTRA serious game is contextualized to rural Nepal. The game teaches 28 learning objectives in three modules: maternal health, neonatal health, and geohazards, through picture matching with immediate audio and visual feedback. User feedback from focus groups demonstrated high engagement, motivation, and usability of the game.