Climate resilience competencies improve people’s capacity to recognize and adopt strategies for mitigating negative climate effects. Especially concerning the built cultural heritage protection in the coastal areas, both professionals and citizens have to be prepared for water-related extreme events, such as floods, sea-level rise, and altered precipitation. Considering these challenges, the authors explore the efficiency of serious video games and describe the process of design and validation of the pilot educational online maze game “Let us save Venice”. More specifically, the main research question motivating the study is to identify what the experience factors and the mini-games are that contribute mostly to raising awareness to climate resilience and built heritage sustainability. The question implies two main research objectives: first, to explore what role user-centered game design plays in creating immersive and enjoyable educational video maze games, and second, to investigate which factors influence user experience and game playability in the design phase, and how they contribute to learnability and raising awareness. The background section of the article focuses on a preliminary study of the educational potential of serious games and introduces the EU-funded project e-Creha. Then, it explores the process of game design, development, and validation, focusing on metrics such as game learnability and game experience. The results outline the main findings that immersion, positive affect, and competence appeared to be the main experience factors contributing to raising awareness to climate resilience and built heritage sustainability. Lastly, the discussion section provides further directions for game improvement and future work.