N3 - The Vast Plain: ★★★★☆☆☆☆☆☆ Now here's where the difficulty kicks in. Collecting keys is similar to how linear gameplay works. Start from the left, and end at the right. It makes key collecting much easier this way. Perhaps the biggest struggle of this course is to not get hit as well as retaining Invisible Wario throughout the collection of the Gray and Blue Key, especially with the zombies.