Using Homemade PowerPoint games as an instructional strategy incorporates elements of game design and constructionism in the classroom using "Microsoft PowerPoint," which is ubiquitous in schools today. However, previous research examining the use of these games has failed to show statistical differences in performance. In the second iteration of a design-based research study, we altered the implementation of a homemade PowerPoint game project in a high school environmental chemistry course, moving the project from a review exercise to a unit project. In addition, we added more structure to the assignment and provided more opportunities for feedback and revision. Student performance on two separate unit tests yielded statistically significant results. On the first unit test, students who did not create games performed better (p = 0.023), while students who created games performed better on the second unit test (p = 0.004) after additional changes were made to the protocol. Further research is needed to confirm these significant findings in light of the changes made to the implementation, as well as examining the instructional strategies embedded in the game project (i.e., microtheme assignments and question writing) in isolation to test the effects of these strategies independent of the games themselves.