This cartridge plays Squash without on-screen scoring. There is no horizontal motion: the player can only move vertically. The wall is fixed and cannot be moved. The ball speed increments as far as the player catches the ball to make it bounce on the wall (the system produces a beep when the ball bounces on the player). Once lost, a manual serve restarts a new game.
Interesting detail: the serve button also resets the ball speed circuit, which stores the ball speed as an electric charge in a capacitor. Because it takes about a second until the capacitor gets its initial charge, a fast game can be start with a short press on the serve button. A longer press will allow the capacitor to get its initial charge, thus starting a game at slower speed.
The circuit board of this cartridge contains very few components, since the game involves one player, the ball, and a vertical line. The resistors set the players size (normal for player 1, infinite for player 2 so as to form a wall), the player field, and the ball motion type. This game differs from Badminton by only one difference: the second player is replaced by the wall. For this reason, both Sparring (Squash) and Badminton use the same circuit board, with only a few resistors placed at different locations to configure either the wall or the second player.