This guide is unfinished.
Leon's Effects
Photon
Go to Neon World (blue door) and interact with the white diamond.
Bug Spray
Go to Glitch World (flashing door) and get caught by the chaser. Interact with the bug sprayer.
Flashlight
Go to Dark World (rainbow door next to Tegan's dream room) and go left. Interact with the flashlight.
At Sign
(It's recommended that you have the Flashlight effect first.)
Go to Impalement World (dark red door) and go inside the red building. Go down the stairs. Inside is a building with three doors. Hit all three switches to make the At Sign in the middle room appear. (Watch out for the chaser. You can scare it away with your flashlight.) Interact with the At Sign.
Leon's Perks
Rain Boots
Go to Neon World (blue door) and step on the little hexagon in the middle of a big hexagon. This will cause an orange trapezoid to appear. Interact with it to get the Rain Boots.
Floppy Disk
Go to Glitch World (flashing door) and go upstairs to find an invisible path. Go through it to get to the Floppy Disk to the left. The path will be visible once you reach the Floppy Disk.
Stress Balls
Go to Arrow World (stoplight door) and hit all three "?" switches in the maze. This will cause the Stress Balls to appear above the door's location.
Radio
Go to Type World (dark green door) and go to the top right to find a chaser blocking another door. Trigger it with the Bug Spray and run inside the door to find the Radio.
Paintbrush
Go to Color World (white and rainbow door) and go right until you see a space surrounded by purple and blue blocks. To the southeast of this part, there are some shapes you can step on. To make a staircase appear, you need to step on the shapes in a certain order: parallelogram, trapezoid, diamond, triangle, and rectangle. Go down the staircase afterwards to find the Paintbrush.