The object of the game is to slide the puck as close to the target as possible. The closer the puck is to the target's center, the more points you are awarded (out of 1000 for each round).
To aim the puck, press and hold on the canvas (or drag your mouse on the canvas). At that point, a red line will appear, showing the direction and magnitude of your shot. When you release, the puck will travel along the path of the line (at the speed given by the length of the line).
Your score for each round is based off of where the puck is when it stops completely.