There are 24 effects in .flow that Sabitsuki can collect. Each effect will change Sabitsuki's appearance and some of them can cause Sabitsuki to have different abilities, or cause different events to happen that wouldn't be able to happen otherwise.
Collecting all of these effects is considered to be the main objective of the game, and once doing so will let you unlock the first two endings.
There are also 3 items known as Empty Boxes that can also be collected, but only after Sabitsuki collects all of the effects, and goes into flow again while already flowing, turning into Rust.
Effects
Headphones
(ヘッドフォン)
Put on headphones.
Appearance: Sabitsuki wears headphones.
Passive Effect: None.
Action: The headphones plays three random notes in succession.
Directions: Found by interacting with the gray DJ NPC in Music World.
Practical Uses: None.
Ghost
(ゆうれい)
Become a ghost.
Appearance: Sabitsuki becomes a ghost.
Passive Effect: None.
Action: Become invisible.
Directions: Found by interacting with the ghost in Flower World.
Practical Uses: When invisible, Chasers will not pursue Sabitsuki, making navigation of certain areas much easier. Needed to enter the Corrupted School.
Iron Pipe
(てつパイプ)
Wield an iron pipe.
Appearance: Sabitsuki hold an iron pipe.
Passive Effect: Some NPCs will run away.
Action: Upon interaction with NPCs, Sabitsuki will strike and kill them. If Shift is pressed, she will hang the pipe over her shoulder.
Directions: Found by interacting with the bloody pipe in Utility Pole World.
Practical Uses: Can be used to obtain money by killing NPCs. Necessary to trigger certain events, such as the Bar Kaibutsu in the Sugar Hole.
Mono Eye
(モノアイ)
Become a Mono Eye.
Appearance: Sabitsuki has one red eye.
Passive Effect: None.
Action: Sabitsuki's eye blinks.
Directions: Found by interacting with the eye surrounded by two ghosts and a pillar in Dysmorphic World.
Practical Uses: None.
Diving Helmet
(せんすいふく)
Equip a Diving Helmet.
Appearance: Sabitsuki wears a diving helmet.
Passive Effect: None
Action: Bubbles float from the top of the helmet.
Directions: Found by interacting with Oreko in her house in Submarine World.
Practical Uses: Interacting with Oreko with the Diving Helmet equipped doubles the amount of friendship points the interaction gives.
Cat
(ねこ)
Become a cat.
Appearance: Sabitsuki has cat ears.
Passive Effect: None.
Action: Lets you transform into a cat.
Directions: Found by interacting with the cat in Rainbow Maze.
Practical Uses: Lets Sabitsuki crawl into smaller areas that she otherwise could not get to.
Broom
(ほうき)
Ride a broom.
Appearance: Sabitsuki rides a broom and has a red ribbon in her hair, similar to Kiki from Kiki's Delivery Service.
Passive Effect: Allows Sabitsuki to go twice as fast.
Action: Dismounts the broom, letting Sabitsuki walk around at normal speed while still wearing the outfit.
Directions: Found by interacting with the witch in the Witch's House in Famicom World.
Practical Uses: None.
Watering Can
(じょうろ)
Hold a watering can.
Appearance: Sabitsuki holds a watering can.
Passive Effect: None.
Action: Can make it rain with 3 different settings, light rain, normal rain, or heavy rain.
Directions: Found by interacting with the ghost holding a watering can in Plant World.
Practical Uses: None.
Whistle
(ホイッスル)
Hold a whistle in your mouth.
Appearance: Sabitsuki holds a whistle in her mouth.
Passive Effect: None.
Action: When used, all NPCs will move in the direction Sabitsuki is facing.
Directions: Found by interacting with the whistle on the ground in Visceral World.
Practical Uses: Can move certain NPCs out of the way.
Gas Mask
(ガスマスク)
Wear a gas mask.
Appearance: Sabitsuki wears a gas mask.
Passive Effect: None.
Action: Sabitsuki raises the gas mask, showing the left side of her face.
Directions: Found by interacting with the plant emitting smoke in Plant Corridors.
Practical Uses: None.
Machine
(きかい)
Become a machine.
Appearance: Sabitsuki has machine parts attached to her body, replacing some limbs.
Passive Effect: None.
Action: None.
Directions: Found by interacting with a desk in Star World.
Practical Uses: None.
Daruma
(だるま)
Become an Daruma.
Appearance: Sabitsuki has no limbs, and there is blood coming out of the appendages.
Passive Effect: Sabitsuki will move slower. She also cannot pinch herself awake due to her lack of arms.
Action: Sabitsuki falls over, walks even slower, and cannot get back up due to having no limbs.
Directions: Found behind the cleaner in the back room in Sugar Hole.
Practical Uses: None.
Slime
(スライム)
Become a Slime.
Appearance: Sabitsuki is green, and looks as if her texture is of slime.
Passive Effect: None.
Action: Sabitsuki turns into a pile of goop, and then regenerates back.
Directions: Found by interacting with the slime at the Northern Wastewater Lake.
Practical Uses: None.
Arms
(うで)
Grow multiple arms.
Appearance: Sabitsuki has five arms.
Passive Effect: None.
Action: Will let you return back to the Entrance at any time.
Directions: Found by interacting with the arm sticking out of the ground in Microorganism World.
Practical Uses: Lets you return to the Entrance from anywhere, instead of waking up each time.
Viscera
(ないぞう)
Viscera is spilling out...
Appearance: Sabitsuki has a big gash in her stomach, and her intestines are falling out.
Passive Effect: None.
Action: Sabitsuki will attempt to put her intestines back into herself.
Directions: Found by interacting with the Onigo body in Womb Maze.
Practical Uses: None.
Psychedelic
(サイケデリック)
Become Psychedelic.
Appearance: Sabitsuki has a glowing appearance.
Passive Effect: None.
Action: Sabitsuki will change colors.
Directions: Found by touching a piece of the wall that is different from the rest in Rainbow Maze, and then interacting with an NPC in Psychedelic Town.
Practical Uses: None.
Handgun
(けんじゅう)
Wield a Handgun.
Appearance: Sabitsuki holds a gun.
Passive Effect: None
Action: When shot, NPCs will move away from Sabitsuki.
Directions: Found by interacting with the dumpster in the Hole.
Practical Uses: Can deter NPCs away from Sabitsuki.
Corpse
(したい)
Become a Corpse.
Appearance: Sabitsuki becomes a slightly purple rotting corpse.
Passive Effect: None.
Action: None.
Directions: Found by interacting with the corpse in the Prison.
Practical Uses: None.
Black Hood
(くろフード)
Wear a Black Hood.
Appearance: Sabitsuki wears a black hoodie.
Passive Effect: None.
Action: Sabitsuki raises and lowers the hood.
Directions: Found by interacting with a hooded body in a bathtub in the Disposal.
Practical Uses: None.
Uniform
(せいふく)
Wear a Uniform.
Appearance: Sabitsuki wears a school uniform.
Passive Effect: None.
Action: None.
Directions: Found in the School by interacting with the Kaibutsu in a circle of desks.
Practical Uses: None.
Tattoo
(いれずみ)
Tattoo your eyes.
Appearance: Sabitsuki has cross tattoos over her, presumably open, eyes.
Passive Effect: None.
Action: None.
Directions: Found by interacting with Smile on top of the balcony in the School.
Practical Uses: None.
Plant
(しょくぶつ)
Become a plant.
Appearance: Sabitsuki has one eye covered by a plant, and is surrounded by plants.
Passive Effect: None.
Action: None.
Directions: Found in the Illusionary Corridors by interacting with the giant flower.
Practical Uses: None.
Dress
(ドレス)
Wear a dress.
Appearance: Sabitsuki wears a black dress and a veil.
Passive Effect: None.
Action: Sabitsuki does a curtsy.
Directions: Found in Snow World by interacting with a dress in one of the buildings.
Practical Uses: None.
Television
(テレビ)
Become a Television.
Appearance: Sabitsuki has a TV replacing her head.
Passive Effect: None.
Action: Sabitsuki turns on the TV, which can help players find certain points of interest in rooms.
Directions: Found by interacting with the TV in Machine Nation.
Practical Uses: The screen depicted on the television changes depending on points of interest in the current world, such as uncollected effects, Chasers, etc, making it useful for quickly learning about a new world.
Instructions
(説明書)
See the game's instructions.
Appearance: None.
Passive Effect: None.
Action: A small description of the gameplay shows on the screen.
Directions: This effect is given when you start the game.
Practical Uses: Can be used to find out how the game works.
Empty Boxes
Empty boxes are three obtainables in .flow that can only be obtained as Rust. These three cannot be seen in the menu, and when obtained it shows an empty message box. The three empty boxes are needed to obtain the Rust Ending.
Demon
(鬼)
The Demon empty box is found in a bloody hole in the wall in the Back Ward. This will then play two cutscenes, and give you the empty box.
Purity
(無垢)
The Purity empty box is found at a machine at the bottom of a set of stairs in Orange Laboratory.
Smile
(笑顔)
The Smile empty box is found in the basement of the School by interacting with a giant mouth.