This is one of the funnest things to do in the game: play pool! This effect is much easier to create than it seems, because the simple physics of the pool ball are automatic.
Create your pool table.
Place pocket sprites (#903) on your pool table wherever you want (realistically in the corners). Use the R
key to floor-align them.
Place pool balls (#901 and #902) on the table. Change their palette values to make them look different. I recommend a palette value of 12 for the Queball.