We present an approach for teaching design patterns that emphasizes object-orientation and patterns integration. The context of computer game development is used to engage and motivate students, and it is additionally rich with design patterns. A case study is presented based on "EEClone," an arcade-style computer game implemented in Java. Our students analyzed various design patterns within EEClone, and from this experience, learned how to apply design patterns in their own game software. The six principal patterns of EEClone are described in detail, followed by a description of our teaching methodology, assessment techniques, and results.