Sometimes it is impossible to catch two balls at once if they're both falling down.

It looks like you have different logic for white and blue. Rather, you should make it conditional: it could be white or blue. To create this random logic, you pick a random number, 1 or 2. Then, you use to ifs to check what it's equal to and in response create an action. If it's 1, drop a white ball, and if it's 2, a blue ball - or in reverse. You can still use a random timer before hand. I think that's how it works, right?

I agree with this, lol. I spent a few minutes trying to figure out how to play,Mobutu it's just impossible sometimes, even if you knock some balls off screen, the cup's speed is limited. You could use while touching(world coordinates)->move to point(TouchingX, TouchingY) on the cup. This should make the cup move instantly when dragged, so it's actually possible (although the player will need to hit balls away sometimes).