Empirical data shows gamification use in education has a generally positive impact on learning, but lacks evidence to explain why the effect exists. Also, only instructors' perspective was considered in traditional gamification products development process. The aim of this study is to examine a peer-based gamification process in engineering education, and to provide some insights into the underlying causes of learning through gamification. The process contains: (1) Solicit concepts that instructors deemed as challenging to learn with a survey; (2) Assign concepts to student teams from two senior-level IE classes (Capstone and Human-interaction Design) to develop gamification products. Survey showed instructors expected gamification products to have more effective visualization and in-time feedback during the practice. A total of 12 gamification products were developed at end. Except for two manufactory-domain games, all other products contained Question and Answer sections, making these products more like "advanced homework": homework with interactive elements added. Lesson learned: Instructors tend to see gamification products as tools to assist teaching; while student focused more on the practice given that student teams were assigned instructions to improve future students' learning. This crucial perspective difference between instructors and students must be resolved before gamification products can be effectively used.