Indonesia is one of the most disaster-prone countries with a low level of community preparedness. Current disaster education methods in Indonesia such as seminars, campaigns, promotions, and educational videos require significant resources but tend to be one-way, less interactive, and cannot simulate actual events. This study aims to complement existing disaster education capabilities through collaborative mobile games that can represent the disaster event with less resources and extend the accessibility and flexibility. As collaboration is one of the keys to sustainable disaster management, a multiplayer game is proposed to facilitate interaction between players. Currently, the majority of multiplayer earthquake and tsunami educational games are offline so that the accessibility is still limited. Development of multiplayer online game is a solution to accommodate more participants in collaborative learning process. A multi-language feature is proposed to overcome the language barrier in collaborative learning across countries. Therefore, a collaborative multilingual mobile game for earthquake and tsunami disaster preparedness education named Tsunami Fighters is developed. The game is a turn-based visual novel game which combines competition with collaboration in its mechanic. The game also evaluates the player's knowledge before and after playing the game. Tsunami Fighters has been tested for students based on game-based learning heuristic evaluation consisting of mobility, usability, playability, learning content, multiplayer and chat components using Likert scale, with overall score 4.13 out of 5. This score indicates that the Tsunami Fighters game can be used as a method for earthquake and tsunami disaster preparedness collaborative learning.