The score is shown using built-in sprites 16 to 25.
The project notes should say "left and right arrow keys to move the paddle at the bottom"; I had to read the code to work out how to play it.
It's too hard for me! I would need a wider paddle. Can kids play it successfully?
It acts like I lose when the ball goes to a corner of the paddle.
Thanks for your comment. Yes, the ball doesn't bounce off the paddle if it only touches the corner (just to make it a little bit more difficult).
Notes added, thanks.