To enhance students' learning motivation and learning interest, scholars have attempted to incorporate game-based learning (GBL) into courses to improve conventional teaching which is mostly carried out using textbooks, presentations, or videos. However, one-tier tests were mainly adopted in previous GBL, meaning that it was difficult to identify whether students answered questions correctly by understanding knowledge or merely guessed the correct answer. Such tests also make it difficult to provide adequate feedback and guidance during the learning process. In order to solve this problem, a two-tier test-based digital gaming approach (TT-DGA) developed using RPG Maker was proposed in this study. It not only provided students with a more interesting way to learn art and view world-famous artworks in the game, but also introduced a two-tier test in the learning process to help students gradually construct professional art appreciation knowledge. To explore the effects of this approach, a total of 62 university students who took an elective art course were recruited in the current study. A quasi-experimental design was employed and the course was conducted physically during the Covid-19 pandemic. One class was the experimental group which adopted the TT-DGA for learning, while the other class was the control group which adopted the conventional gaming approach (C-DGA). The results showed that the TT-DGA could significantly enhance students’ learning achievement of art appreciation, learning motivation, learning attitudes, and flow experience. Based on the behavioral analysis, students in the experimental group were more active than those in the control group in terms of reading art history materials, watching videos, engaging in tests, and playing the game again. Finally, the interview results uncovered that the two-tier test could help students conduct self-inspection, confirm the accuracy of their understandings of knowledge, and correct misconceptions, and that DGBL made the art course more interesting.