What is happening right now?

Thanks you for help. Now I understand this.

Where does the 30-second delay come in? When does it start? What, if anything, happens during the delay? And what happens when the 30 seconds is up? There are two things about the code provided that should be noted. One is your loose use of the getWorld method throughout the class. Once: the line <Code Omitted>is executed, that method will thereafter return a 'null' value. That means you cannot execute any method or access any fields using it or an error (NullPointerException) will ensue. So, in the checkBoundaries' method, the second if should have else before it as well.. As an alternative, you can combine the logic checking to: <Code Omitted>or, <Code Omitted> Another place where this comes into play is the order of calls in the act method. If the second act method executes the removal of the object, then a error will occur during the call to the destroyEnemies method. Switching the two method won't work because this method also may remove this object (which will cause an error in the first method). You will have to check the returned value of getWorld for a null value before moving on to the second method call: <Code Omitted>

Thank you, it works. I guess I was thinking wrong.

In a World subclass, you would use: <Code Omitted>

currently testing that method out at the moment ill keep you updated... I was going to test setPaintOrder (class) method. I'll keep you posted thanks for the feed back.