Sparks need a path. It is your job to complete the circuit so that the spark can make it to the middle and light up the board. But, the circuits are all messed up, even though the spark has a pre-determined path. You will watch the spark and click the white lines necessary to keep the spark moving. If he hits the end of one of the lines, you'll have to start over. Each level will add another spark with a different path, so it gets very difficult. Go ahead and see how many sparks you can keep on the right track.