Gamifying online homework activities and learning assignments is an effective approach to facilitate students' engagement and enjoyment. While incorporating game elements to gamify homework and learning assignments promoted positive psychological and learning outcomes, the mere use of these elements brings several flaws associated with the gameful design that constrains the perceived gameful experience and increases the cognitive load of students during homework achievement. This research demonstrates the micro design as an innovative approach to gamify homework assignments and investigates its effects on perceived gameful experience, intrinsic motivation, engagement, and cognitive load. Forty-three primary school students were randomly divided into two groups, i.e., experimental and control groups. The experimental group with the micro gameful design of homework activities and the control group with conventional gameful design. The results provided empirical evidence on the impact of gamifying online homework while there are no significant differences between the groups on gameful experience, motivation, and engagement. The micro design approach is effective for reducing the cognitive load of students when accomplishing homework tasks. The current data highlight the importance of enhancing the gameful design approaches and patterns when gamifying learning assignments and developing motivational cognitive affordances that promote behaviour change and task completion.