Are the balls going through each other or bouncing off each other? To start press the green flag, then you get to watch through my boring intro. Once the balls appear press the up arrow then when they are at the top of the screen press the down arrow. You can do this as many times as it takes for you to figure out if the balls are bouncing or going through each other. Comment down below whether you think they are bouncing or or going through each other. Have fun!