//package spaceinvaders;

import info.gridworld.actor.ActorWorld;
import info.gridworld.grid.*;

public class SpaceInvaders {
	public static void main(String args[]) {
	    Grid g = new BoundedGrid(20, 20);
		InvaderWorld world = new InvaderWorld(g);
		
		for(int i = 2; i <= 8; i+=2)
		{
		    for(int j = 4; j <= 14; j+=2)
		    {
		        world.add(new Location(i, j), new Enemy(Location.EAST, 3));
		    }
		}
		world.add(new Location(19, 10), new Ship(5));
		world.add(new Location(17, 8), new Wall(4));
		world.add(new Location(17, 10), new Wall(4));
		world.add(new Location(17, 12), new Wall(4));
		world.show();
	}
}

@@ -58,44 +58,162 @@
 ctor
-World;%0D%0Aimport info.gridworld.grid.*
+;%0D%0Aimport info.gridworld.actor.ActorWorld;%0D%0Aimport info.gridworld.grid.Grid;%0D%0Aimport info.gridworld.grid.BoundedGrid;%0D%0Aimport info.gridworld.grid.Location
 ;%0D%0A%0D
@@ -295,16 +295,23 @@
     Grid
+%3CActor%3E
  g = new
@@ -322,16 +322,23 @@
 ndedGrid
+%3CActor%3E
 (20, 20)

Fix compiler warnings