Training in critical thinking is essential for the professional development of journalism students. To achieve this goal, this study developed a gamified platform and a blended learning curriculum. During an 18-week experimental instruction period, a series of instructional activities, which included online discussions as well as classroom lectures and discussions, were conducted to enhance 32 journalism students' critical-thinking dispositions and skills. Repeated measure analysis of variance on test scores and analyses of open questions found that the participants significantly improved their critical thinking skills and dispositions through the gamified platform with the experimental instruction in a blended learning environment. The findings suggest that providing clear goals, challenges and quests, feedback, competition and cooperation, actual grading and visible status, access/ unlocking content, onboarding time restrictions, freedom of choice, and new identities and roles, as well as avoidance of over-justification, contributes to achieving a "meaningful gamification" experience, which may further lead to self-determined learning in critical thinking.