Fig 2. One example of the game playing “whack-a-mole”.

In this mole-themed version of “whack-a-mole”, a step-sensing pad is placed on the floor, and the participant treads on the pad as fast as possible when virtual moles randomly appear on the holes of the TV screen. The game has three difficulty levels (A). The higher the difficulty level is, the faster the moles appear, and the more moles appear simultaneously. Level I has one mole (B shows that the player failed to stomp the mole into the hole with his left foot; C shows the player successfully stomping the mole into the hole with his left foot), Level II has two moles, and Level III has three moles (D shows the player successfully stomping a mole with his right foot but failing to stomp another mole with his left foot). The score of successful stomps appears in the right bottom corner of the TV screen with auditory feedback, and the remaining time appears in the left bottom corner of the TV screen during play. After the game has finished, the final score appears on the screen (E).