Game: Added credits and better images

Game-2/src/Game/Missile.java

@@ -1,8 +1,10 @@
+// Origin: https://zetcode.com/javagames/movingsprites/
+
 package Game;
 
 public class Missile extends Sprite {
 
-    private final int BOARD_WIDTH = 390;
+    private final int BOARD_WIDTH = 800;
     private final int MISSILE_SPEED = 2;
 
     public Missile(int x, int y) {

Game-2/src/Game/SpaceShip.java

@@ -1,3 +1,5 @@
+// Origin: https://zetcode.com/javagames/movingsprites/
+
 package Game;
 
 import java.awt.event.KeyEvent;

Game-2/src/Game/Sprite.java

@@ -1,3 +1,5 @@
+// Origin: https://zetcode.com/javagames/movingsprites/
+
 package Game;
 
 import java.awt.Image;

Game-2/src/Game/TheGame.java

@@ -1,3 +1,5 @@
+// Origin: https://zetcode.com/javagames/movingsprites/
+
 package Game;
 
 import java.awt.EventQueue;