Gamification has been used in education since the early 2010s, however, the empirical studies on the effectiveness of gamification have yielded inconsistent results. Without a clear understanding of how gamification works, and which gamification design elements have a higher potential to influence learning outcomes, gamification intervention may not achieve the desired results. This study aimed to examine the factors that contributed to the successful implementation of gamification in higher education, and to identify the design elements that had most influence on student learning outcomes. Data was collected from the empirical studies conducted between 2014 and 2023. Data analysis was conducted using logistic regression and Chi-Square tests. Two gamification design elements, "Social Interaction" and "Leaderboards," were found to have significant influence on student learning outcomes. This study provided insights for college instructors and instructional designers in the design of gamification intervention in instruction. Implications for practice and future studies were presented.