This design-based research study examined the effects of a game design project on student test performance, with refinements made to the implementation after each of the three iterations of the study. The changes to the implementation over the three iterations were based on the literature for the three justifications for the use of homemade PowerPoint games in the classroom: constructionism, microthemes, and question writing. A review of the literature for the justifications found that the game project, as implemented in previous studies using homemade PowerPoint games, did not align well with the justifications. After three iterations of the study, students who created homemade PowerPoint games did perform better on assessments than students who either did not create games, created games as a review, or created games as part of an unstructured unit project. However, these differences were not statistically significant. As part of the third iteration, two of the individual justifications were tested in isolation to whether gains could be seen without creating games. While the students who were part of interventions involving microthemes and question writing did perform better than students who did not receive the interventions, the differences were not statistically significant. Future research in the area of game design as an instructional tool should look to replicate these studies, as some of the sample sizes were small. Future research should also examine additional changes to the implementation of a game design project, including the use of other programming languages.