added instruction panel.

Assets/Scripts/Menu.cs

@@ -7,6 +7,7 @@ using UnityEngine.UI;
 public class Menu : MonoBehaviour
 {
   public GameStateTracker gameStateTracker;
+  public GameObject instructionPanel;
   public GameObject gameUI;
   public GameMaster gameMaster;
   public GameObject menuPanel;
@@ -69,6 +70,13 @@ public class Menu : MonoBehaviour
 
   void Update()
   {
+    if(Input.GetKeyDown(KeyCode.Return)) {
+      instructionPanel.SetActive(!instructionPanel.activeSelf);
+    }
+    if(instructionPanel.activeSelf) {
+      return; //RETURN when instructionpanel is shown.
+    }
+
     if (Debug.isDebugBuild)
     {
       for (int i = 0; i < 10; i++)
@@ -217,6 +225,7 @@ public class Menu : MonoBehaviour
         }
       }
     }
+    
   }
 
   //returns the player number (3 for player three). returns -1 when there is no free player slot.