The best part about Tiny Tennis is that you can play it against yourself, making it easy to test the game and experiment with different parts of the game. Now, when you run the file from your terminal, a window that looks like this should pop up:

The ball should start moving immediately toward one side or the other of the screen. You can test the game by making sure that the paddles on each side of the screen are able to hit the ball and that they do not go outside of the screen space. You can test the scoring mechanism to make sure that the appropriate player is getting the points for each shot that they make past the other player. Then, you can invite others to play the game with you.

If you are not happy with parts of the game, you can change them. For example, you might choose a different color for the ball, paddles, and the screen. Maybe you want the paddles to be longer or shorter or, perhaps, thinner. Maybe you want to make the ball bigger or smaller by changing the...