Score as many times as you can and reach the mark required by each level. In the 2 players mode, you can play in one of 2 modes: in the TEAM MODE, both players join to advance through all levels; in the RIVALRY MODE, both compete against each other as follows: they select one level and play 2 minutes face to face, and wins the one that makes more points. In both cases you'll find mutiple bonus items, like green and red apples or golden coins (that give you points), clocks (that give you extra time), flowers (that temporarily freeze the moving baskets), etc.
Player 1 runs with the arrow keys left/right, takes the ball with the arrow key down, keeps pressed the arrow key up to aim and releases it to launch. Player 2 uses the A, S, D and W keys as if they were the arrow keys to do the same actions.