Tennis For One - Infinity is a variation on the default Tennis For One game. Just like the default version, Tennis For One - Infinity is played on one screen, and is a single player game where one controls the vertical position of a tennis racket, using it to hit a ball into the target. However, Tennis For One - Infinity rewards how quickly the player manages to get the ball into the target as well.
The game has multiple levels, and in each level the ball starts in the center of the screen. Once the user clicks, the ball moves right in a straight line with some random velocity, capable of bouncing off the top, bottom, and left walls. Each level has a timer that begins counting down upon the user's first click.
The user controls a racket along the right wall, using it to direct the ball into the target, some highlighted area along the left wall. The direction of the bounce depends on where the ball hit the racket. If the ball hits the target before the timer reaches 0, the next level is loaded and started with another mouse click. If the timer reaches 0, the player is sent to the previous level again. If instead the ball hits the right wall (beyond the racket), or if the timer reaches 0 on level 1, the game ends, and the highest level completed is displayed as the score.
The direction at which the ball bounces off the racket depends on where it hits the racket. This helps player direct the ball into the target.
The timer counts down from a constant number for all level. This number can be determined after testing for a reasonable difficulty.
As the level number increases, the target size decreases so that the game becomes progressively harder. The target position is randomly decided for each level, but the size is deterministic.
