Physics Playground: Presenting 3D lecture content using Unreal Engine This paper discusses strategies for teaching game design using custom 3D game demos made in Unreal Engine. Lectures on video game technologies can be brought to life by including images or videos in PowerPoints, making the content more engaging. However, we can go one step further by incorporating interactive 3D content made with video game technologies such as Unreal Engine. To teach topics such as game engine physics I created Physics Playground, an interactive project which showcases various principles, allowing me to easily demonstrate concepts using real-time 3D, instead of relying on lecture slides or videos. In the supporting labs, students can explore the project themselves and extend or customise it to gain a better understanding of game engine physics. In other instances I have created projects which similarly demonstrate various other principles of game development ranging from level design and player interactions to systems for implementing dynamic sound effects and music. This paper discusses these projects and related pedagogical concerns. By sharing these practices, the paper aims to stimulate thought on ways to harness the latest game engine technologies to make lecture presentations more engaging for students.