Some segments end up hiding (not supposed to); so, 600 arrives before the grid is actually filled. Still trying to solve the problem (any help would be appreciated).

Not sure I understand -- using the menu to reset the game or switch game works fine at home, but the uploaded scenario seems to want to 'stop' when these are used in 'Greenfoot'.

Think you have found a neat image? Leave a comment with coordinates and parameter values and, if worthy, I will post that location with your name!