In World 5 (Cloud World), the first available mushroom house has a Tanooki Suit. Get it and beat levels until you get to the cloud part of the world by beating the spiral tower. The game offers to save your game. Save it, then get game over. When you continue, you keep the Tanooki Suit you got at the mushroom house, and the mushroom house has returned! All of the other levels remain defeated as well, though the spiral tower remains standing, so you cna beat it and save your game, get game over, and get another Tanooki Suit each time! The suits make good replacements for leaves, mushrooms, and useless items (like music boxes) in your item list.

Glitch only works for World 5 due to the ability to beat the spiral tower as many times as you want and save after each time.