Fix warning of unused iterator

Game.gd

@@ -17,7 +17,7 @@ var playerActionsLeft = ["p1_left", "p2_left", "p3_left"]
 var playerActionsRight = ["p1_right", "p2_right", "p3_right"]
 
 func _ready():
-	for k in range(levelNames.size()):
+	for _k in range(levelNames.size()):
 		levelScenes.append(null)
 
 	if levelToLoop: