The purpose of this study is to explore the effect of a pedagogical model of digital games on students' scientific competencies that are advocated by the Programme for International Student Assessment (PISA). As a single game-based learning strategy may not be enough to enhance such competencies, the online game in the current study incorporated the design of the proposed pedagogical gamification, assessment, modeling, and enquiry (GAME) model. The participants were 69 sixth grade students at one primary school in Taiwan. A quasi-experimental design was adopted. The experimental group students learned with the GAME model, whereas the comparison group students only learned with traditional learning way. The results showed that the learning gain in scientific competencies of the experimental group was better than those of the comparison group. This study revealed that the GAME model has potential to promote students' PISA scientific competencies. It is suggested that the integral GAME model may serve as one kind of strategies to enhance students' scientific competencies.