As intelligent devices become increasingly prevalent, digital cognitive training tools are becoming more accessible, thereby creating new opportunities for the advancement of serious games. However, existing serious games for cognitive training in older adults primarily focus on task-oriented activities, with comparatively limited research into effective game mechanics and user experience. To explore the potential of gamified tools in the training and enhancement of cognitive function in older adults with mild cognitive impairment, a framework is proposed to design a cognitive training serious game for older adults on tabletop user interface with spatial interaction. Then, we employed participant observation and in-depth interviews to understand the behavioral responses and cognitive load of older adults during their engagement with digital tools. Through a within-subject design, the study aims to enhance the engagement of gamified tools among older adults, thereby improving their cognitive functions and offering new approaches for the prevention of mild cognitive impairment in older adults.