Reading is the basis of most learning but is regarded by students as a boring activity in Hong Kong. Therefore, schools in Hong Kong have launched different reading programs to promote reading. One of the successful examples is Reading Battle which gamifies the reading comprehension assessments with points, levels, e‐badges and leaderboard on an interactive learning platform. This study looked into how gamification affected the flow experience of students and discussed to what extent the nine flow dimensions were experienced by them, especially the heavy users of the gamified learning platform. This case study chose nine students from four different elementary schools in Hong Kong and adopted a mixed method such as questionnaires and interviews. While many students first did it for external motivation such as getting more points and ranking high on the leaderboard, the study found that the heavy users of Reading Battle became committed to reading and many enjoyed the flow experiences where they seemed to forget about time and discomfort and truly enjoyed the reading process.