Update

src/main/java/MenuFrame.java

@@ -9,4 +9,12 @@ public class MenuFrame extends JFrame {
         this.add(panel);
         this.setTitle("Main Menu for Ping-Pong");
         this.setResizable(false);
+
+        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        this.pack();
+        this.setVisible(true);
+        this.setLocationRelativeTo(null);
+    }
+
+
 }