Add instruction animate mobs

Enemy.gd

@@ -9,6 +9,7 @@ var mob_types = ["walk", "swim", "fly"]
 
 func _ready():
 	$AnimatedSprite.animation = mob_types[randi() % mob_types.size()]
+	$AnimatedSprite.play()
 
 func _on_VisibilityNotifier2D_screen_exited():
 	queue_free()