This is a copy of the original Scratch Pong game, re-written in GP to show some of the differences and similarities between Scratch and GP
There are 3 main differences between the two sets of code
Creates the paddle image and moves it near bottom of screen
Make the paddle track the mouseX position in the equivalent of a forever loop. Notice the need for a wait (for screen refresh) at the end of the loop
Create the ball image by first setting whole image to transparent and then filling a circle in the middle of it
Move the ball to the top of the screen, point it in a random downwards direction and just wait until it touches the redline
Loop moving the ball 4 steps, bouncing off the edges if needed
The main script in the program.
Loop and if the the ball touches the paddle, change its direction to bounce off it (and add a bit of randomness to it)