Kahoot!, a game-based student response system, is increasingly being incorporated into classrooms to maintain student engagement, improve classroom dynamics, and enhance learning outcomes. However, empirical studies exploring how using Kahoot! affects university students' learning, particularly in China, are scant. This exploratory, one-group, mixed-methods study investigates the effects of Kahoot! usage on pre-service teachers' academic achievement and perceptions within a Modern Educational Technology course in China. The results reveal that integrating Kahoot! into the course appears to positively impact students' test scores. Pre-service teachers maintain positive perceptions of using the tool in terms of its perceived learning effect, expected outcome, entertainment, engagement, and competition. Furthermore, the majority of pre-service teachers would like to use Kahoot! for future learning and teaching. The study underscores the potential of Kahoot! to improve pre-service teachers' learning outcomes, providing implications and recommendations for future practice and research.