Abstract Over recent decades, serious games have become a promising intervention approach for addressing psychological problems by providing users with computerized, engaging, and interactive experiences. An innovative serious game, Traveler, has been developed specifically as an intervention tool for managing posttraumatic responses immediately after trauma. The game incorporates the principle of visuospatial interference, the core elements of Tetris, such as spatial displacement and mental rotation, and the critical phases of eye movement desensitization and reprocessing. To test the intervention efficacy and feasibility of Traveler, we conducted a randomized controlled trial involving 105 young adults. Participants were randomly assigned into three groups: a wait‐list control group, a group undergoing five‐session written exposure therapy, or a group engaging in one session of Traveler gameplay. Outcome measures included intrusive memories (i.e. vividness of traumatic images, disgust at traumatic images, flashback frequency, and flashback impact) and posttraumatic growth measured by the Posttraumatic Growth Inventory. Traveler significantly outperformed the control and written exposure therapy groups in reducing intrusive memories and enhancing posttraumatic growth, with effects persisting at a 30‐day follow‐up. Thus, Traveler offers a promising brief and early intervention technique for addressing posttraumatic responses. Yet, its clinical applicability requires further investigation.