This research aimed to design and develop a digital platform-mediated tourism system for self-service information in small-town destinations. It focused on a case study performed in Koh Raet, Surat Thani province, Thailand. The system consists of the Tourism Information Service (TIS) system and a digital game for discovering Koh Raet. The TIS System is designed for self-visiting activities in Koh Raet.  Furthermore, the digital game for exploring and discovering Koh Raet was also integrated with a QR code, with the objective of improving tourist experiences. A qualitative approach was conducted, followed by managing the system development, and finally, the system evaluation related to the efficiency of the proposed system was performed. To evaluate the system, we gathered qualitative data from an online questionnaire. Based on the results, we conclude that the participants were highly satisfied with the system's performance. The research contributes to empowering small-town tourism by combining tourism information services and gamification into a digital-platform-mediated tourism system. Another contribution is to provide a self-service experience for travelers in small-town destinations, offering reliable and up-to-date information about the destination. Furthermore, it is intended to foster small-town tourism promotion, and boost tourism activities in small-town destinations in sustainable ways