It's a game of music and math. Play with headphones or external speaker for full experience. The player is given a current value and a target value. The goal is to attain the target value with the current value. You must do this 10 times to win a level.

We start a node, a value, and a target value. We can move from a node to any other connected node. When you move to a node you add the value associated with that node to your current value. This addition however is performed modulo some integer. Recall this is the remainder after dividing by the modulus. We use 12 as the canonical modulus, but the modulus starts at 3 to make the game easy for beginners. Tap and hold the upper left hand board to obtain a menu that allows you to choose more difficult puzzles. Start a new game after choosing a new puzzle set.

We use 12 as the canonical modulus for a reason. We assign each number 0, 1, 2, ..., 11 a musical note. In this way, the player not only creates a melody as they play, but also is able to hear the interval created between their current value and the target value.