@Velociraptor06, I do not know what I can add to what comments are already in the code. Please ask your specific questions here. Really, the only thing I can add (since you asked about 'World', 'SWorld', and 'MyWorld') is this: World: this class is supplied by greenfoot; all other world classes are subclasses of this class. SWorld: is a support world for a scrolling world (used as a superclass) MyWorld: a world demonstrating the use of the SWorld scrolling superclass