A serious game application was developed to test the working memory of 40 subjects. The application is based on the well-known memory game ”Pairs,” using auditory, visual, and mixed modalities in different resolutions. Evaluation of completion times and error rates revealed no significant difference between auditory and visual memory. On the other hand, playing the game in the mixed modality resulted in better outcomes. Furthermore, speech samples and auditory icons were generally superior to measurement signals in the case of the highest resolution (24 pairs).