If you are controlling the orange cat, use w to go up, s to go down, a to go left and d to go right. If you are controlling the grey cat, use i to go up, k to go down, j to go left and l to go right. The aim is to hit the ball, then it will go in the hoop. If you get it in the hoop, you win. You might need to stay near the hoop to get the ball into the hoop. This is a 2 player game.
Sometimes the ball won't react when you touch it, so just keep trying until you get it. If it really doesn't work, tell me in the comments.
