Sepedi dithai (riddles) are a cognitively demanding sub-genre of indigenous folklore, yet their pedagogical potential remains largely confined to oral and print modalities. This study reports a design-based research study in which ten Sepedi dithai were integrated into a browser-based educational game and deployed to learners through Netlify. The study was guided by Vygotsky's sociocultural theory, Anderson and Krathwohl’s revised taxonomy of educational objectives, Plass, Homer, and Kinzer's foundations of game-based learning, and Mishra and Koehler's Technological Pedagogical Content Knowledge framework. A three-iteration design-based research cycle was conducted with four Sepedi home language teachers and twenty Grade 7 learners. Data were generated through non-participant classroom observations, semi-structured post-play interviews, game-log analytics, and document analysis of learners' typed in-game responses, and were analysed thematically. Findings indicated that the game sustained engagement with higher-order reasoning across inferential, evaluative, and creative riddle categories, stimulated culturally grounded reasoning in which learners drew on the indigenous concept of botho (humanness), extended teacher scaffolding into asynchronous modes, and strengthened the home-school connection through multigenerational play. The article proposes that carefully designed, culturally situated educational technology can amplify rather than displace indigenous folklore pedagogies and offers a potential replicable design pattern for other indigenous African languages.