FOG/guide

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.

Banshee
(It's recommended that you have the Flashlight effect first.) Go through the gray door with three rectangles on it. Go left down the stairs to a dark passageway. With the Flashlight effect equipped, go down and left as far as possible to another red door. Head down the stairs to another door. In the next area, follow the footprints and take a right at the first fork. Go in the following directions at each fork: right, right again, up, right, up, left, and up. Interact with the mound with a face.

Leon's Perks
Use Perks with the "????" skill. As of now, only the Laptop Perk has a function.

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.

Laptop
Go to your Dream Bedroom and interact with the laptop. But, you can only get the Laptop when you're at 1 HP, otherwise the laptop will keep glitching out. Your HP is randomized every time you sleep. It's best to get this perk early on in the game so you have a better chance of getting down to 1 HP.

Alternate
Go to Arrow World (stoplight door) and hit all three "?" switches in a certain order: the one to the left, the one to the right, and the one above the door. Interact with the sun afterwards.

Onion
Go to Dark World (rainbow door by Tegan's dream room) and go through the maze, avoiding chasers. Once you reach the end, you'll be in Side World (daytime). Go through a gate and go all the way to the left to reach another maze. Find and interact with a bloody filing cabinet to get the Onion.

Mouse
Go through the door right in front of Emory when they enter the Nexus. Go all the way downstairs and through the bottom door. Exit to the south outside. Go up the alleyway to enter Side World. Go through the second gate you see to enter Dark World. Get caught by a chaser and go down the stairs back to the beginning of Dark World. Go through Dark World's door to get back to the Nexus. Go through the cream-colored door to enter Emory's dream bedroom. Interact with the bloody desk to get the Mouse.