Either re-share the scenario with the 'Include source code' checkbox checked or start a discussion supplying the code you have so far and an explanation of what is not working properly.

To fix the ball out error: in the 'act' method of the Ball class, switch the order of the 'checkOut' and 'checkFly' calls. Also, in the 'checkOut' method, remove the 'gameOver' call. Will reply about counter shortly.

In the ball class, in the 'checkFly' method, add the following line inside the if(fly != null) block: ((Counter)world.getObjects(Counter.class).get(0)).add(5);

You may want to add a counter in your world class to track the number of new balls created and if it reaches a certain value, then 'gameOver'.