Crowbar / (バール)Edit
Enter the top-right door to Gouged Eye World. Go left from the door. You should eventually find a crowbar in a pool of blood above you. Interact with the crowbar to get the effect.
Metal / (メタル)Edit
Enter the bottom-left door to Bright Tile World. Go left a bit and down from the door and interact with the stick of red metal on the ground.
Snail / (かたつむり)Edit
Enter the bottom-right door to Flower World. Go south-west and find/interact with the snail.
Chinese Dress / (チャイナ服)Edit
Enter the top-left door to Purple Wall World. Go right and down from the door and interact with the dress on the stand.