Here is a list of the current effects present in Yume 2kki, as well as their locations and instructions on how to get them.
Please remember that this game is still a work in progress, and because of that the instructions here may become outdated at any time in the future.
Bike (Motorcycle)
(Effect recommended to have before retrieving: none)
From The Nexus, enter Garden World. The effect is located directly southwest from the entrance.
This effect doubles Urotsuki's speed, allowing for much quicker travel. Also, if one holds down the interact key long enough, Urotsuki will pop a wheelie in place. The name "Motorcycle" comes from Western fans of the game, as the game refers to the effect as "Bike".
BoyFile:Effect boy.png
(Effect recommended to have before retrieving: Motorcycle)
From The Nexus, enter Geometry World. Travel directly north from the entrance, then turn to the west once you pass a C-shaped line on the ground to your left. Continue traveling west until you see a door in a opaque teal block (if you loop and don't see it, move two or three steps north, then continue to the west), and enter the doorway. Head east down the teal path and enter the door on the teal object at the end of the path. Once you emerge in a yellow-and-black room with a maze, go to the southern end of the boxed-off area that you're in and enter the maze (make sure to avoid the patrolling ghost). Transverse the maze until you encounter a yellow-framed doorway, then enter the door and travel north along the path until you pass through a second doorway. Move through the second section of the maze until you encounter yet another doorway (there should be a number of white ghosts in an enclosed area within sight of this door). Go into this door, then interact with the blue object at the far end of the room until it makes a different sound. Exit the room, then interact with the rainbow-flashing outline of a human to obtain the effect.
Chainsaw 
(Effect recommended to have before retrieving: none)
From The Nexus, enter Graveyard World. Travel roughly east-northeast until you find a vomiting heart, then pass through its open mouth and enter the door on the western wall in the room in which you appear. Travel west through the Hospital's reception room and go through the opening on the western wall. Pass through 3 segments of the hallway (you'll go by 9 doors), then enter the first door in the 4th hallway segment and go through the opening on the western wall in the small room through the door. Continue west through the oddly-floored hallway and pass through the entryway into the Hospital Outskirts. Go directly south from the entrance, then head due west once you reach the southern wall of the Outskirts. Step on the red circle, then enter the mouth of the vomiting diamond located to the west of the entry point (that is, the red circle that brings you back to the Outskirts) 3 times, looping around from the back to the front to re-enter it. Interact with the chainsaw stuck in the ground in the completely black area to obtain the effect.
Lantern 
(Effect recommended to have before retrieving: none)
From The Nexus, enter Forest World. Travel northwest from the entry point until you see a large hole partially blocked off by traffic cones. Enter the hole, travel south at the first intersection near the cave's entrance, and continue south until you reach the southernmost wall. Head east (and south/north as necessary) and you should find the effect at a dead-end.
Fairy 
(Effect recommended to have before retrieving: none)
From The Nexus, enter Onyx Tile World. Move along the eastern path until it opens up, then head northward, going to the west at the intersection you should encounter. Continue north until the pink, worm-like object comes into view, at which point begin moving east-northeast until you find a taxi. Interact with the taxi to warp to the Highway. Travel southeast from the entry point of the Highway until you find a small building with a Robot Guard standing next to it. Bypass the Robot Guard and enter the building, then interact with the fairy to obtain the effect.
This effect can be used to fly over some gaps in terrain and to fly through small holes in walls that would otherwise be inaccesible. In older versions, this effect was located in Pokemon World.
Spacesuit 
(Effect recommended to have before retrieving: Motorcycle, Lantern)
From The Nexus, enter Geometry World. Travel west-southwest until you encounter a square block with a door set into it (it should be next to a row of other doorless blocks). Go through the door to enter the Dark Museum. Travel north and go through the northern door, then walk west down the hallway and enter through the door on the northern wall at the end of the hallway. Go north until the room opens up, then walk west until you see a cartoony mailbox. Interact with the mailbox to enter Flying Fish World. Navigate through the elevator systems and you'll eventually come across the effect lying on the ground (you'll pass by a boarded-up door on the way; this is Smile-san's room).
This effect allows you to pass over some gaps in terrain, and it is required to enter Space. Holding down the interact key will cause Urotsuki to do a somersault in place.
Glasses 
(Effect recommended to have before retrieving: Motorcycle, Lantern)
From The Nexus, enter Geometry World. Travel west-southwest until you encounter a square block with a door set into it (a row of smaller blocks should be directly to the right of this block). Go through this doorway to enter the Dark Museum. Move north and go through the northern door, then go west down the hallway and pass through the northern door at the end of the hallway. Head north until the room opens up, then interact with the cartoony mailbox located west of the door you just exited to enter Flying Fish World. Ignore the elevator entrance and instead travel west and interact with the identical cartoonish mailbox to teleport to the Museum (distinct from the Dark Museum). Go through the eastern door and interact with the moving glasses on the pedastal to obtain the effect.
This effect reveals some hidden items and modifies the appearance of a few visible object.
Rainbow 
(Effect recommended to have before retrieving: none)
From The Nexus, enter Theatre World. The effect is located directly southeast of the entry point.
This effect illuminates obscured tiles or objects, and can generate a rainbow in some rainy areas.
Wolf 
(Effect recommended to have before retrieving: none)
From The Nexus, enter Mushroom World. Go west from the entry point until you find a white pavement trail, then follow the trail in a northwesterly direction until you find a green teleporter. Interact with the teleporter to go to the Bug Maze. Travel west along the path until you are forced to turn north, then take the northeastern path at the intersection. Follow the path until the next intersection, then go north at the intersection and follow the trail pointed to by the yellow arrow. Interact with the monochrome sign at the end of the trail to enter Sign World. Travel directly south from the entry point until you run into a sign, then go east until you encounter a heart. Head north from the heart and interact with the blue and white signpost to enter the Teleport Maze. Enter the teleporters in the following order: Right, right, up, right, right. Step on the white teleporter to your north to enter an enclosed beach area. Move east until you find a gray-haired NPC; interact with the NPC to obtain the effect.
This effect makes Urotsuki howl, which causes most NPCs to move away from her. Notably, this effect can be equipped on top of the Motorcycle effect for a mixed effect, allowing you to howl while on the motorcycle.
Eyeball Bomb 
(Effect recommended to have before retrieving: Fairy or Spacesuit)
From The Nexus, enter Toy World. Go south (the Fairy and Spacesuit effects allow for easier navigation of the slippery floor, if necessary) and pass through the east-facing door in the blue blocks to enter the Mini-Maze. The effect is located deep within the maze (the specific directions are too lengthy to list here), and it is visible on the maze's map.
This effect allows you to return to the Nexus at will, similarly to the Medamaude effect from Yume Nikki. Notably, this effect can be equipped but does not function in underwater areas.
Telephone
(Effect recommended to have before retrieving: none)
From The Nexus, enter Marijuana Goddess World. Travel south and east across the body of the goddess until you reach the bottom row of tiles on the shape, then head due east until you find a pink doorway shaped similarly to a cat's mouth. Go through the doorway to enter the Dark Room. Enter the southern doors in the next two rooms, and you should arrive in a room with a faceless, bat-winged girl. Interact with the moving telephone to obtain the effect.
This effect triggers reactions in some NPCs, and is required to get the Twintail effect.
Maiko
(Effect recommended to have before retrieving: none)
From The Nexus, enter Mushroom World. Go west until you encounter a white pavement path, then follow the pavement path in a northwesterly direction until you find a green teleporter. Interact with the teleporter to enter the Bug Maze. From the entry point, go west along the path until you are forced to go north, then take the northeastern trail at the intersection. Follow the path until the next intersection, go north at that intersection, and head west at the next intersection. Take the southern branch off of the western trail and walk between the two humanoid figures to enter The Hand Hub. Travel southeast from the entry point (ignore the other portal that's visible from the entry point) then take the closest northeast path. Interact with the portal at the end of this path to go to the Shinto Shrine. Go due north from the Hand Hub's entry point and take the main entrance into the shrine. The effect can be obtained from the animated geisha outfit, which is located roughly northeast from the main entrance's entry point.
This effect allows you to take the place of the geisha woman that manages the hotel in Japan Town, and it allows you to view the Odorika event. Holding down the interact key will make Urotsuki bow.
Penguin
(Effect recommended to have before retrieving: none)
From The Nexus, enter Urotsuki's Dream House. Interact with the video game system next to the TV set. Once the game begins, walk along the eastern path (going up and down the ladders as necessary), then hold down the interact key to slide past the looping segment of the path. After that, go onto the next map, climb up the ladder, and face the ledge. The effect will automatically be in the menu the next time you go to sleep.
As described above, holding down the interact key causes Urotsuki to slide and bypass some events. In addition, this effect makes Urotsuki swim if it is equipped in an underwater area.
Bug
(Effects recommended to have before retrieving: Chainsaw)
From The Nexus, enter Mushroom World. From there, go west until you encounter a white pavement path, then follow the path in a northwesterly direction until you find a green teleporter. Interact with the teleporter to enter the Bug Maze. Move along the west path, go north at the first intersection, and interact with the giant flower to enter the Scenic Outlook. Equip the Chainsaw effect and attack the creature standing in front of the gray pillar. When it begins chasing you, lead it out of the narrow passage, then enter the now-unblocked passage and interact with the gray pillar. Travel north from the entry point and interact with the gray-and-green object surrounded by fires to obtain the effect.
This effect causes some NPCs to move toward you, similarly to the Cat effect from Yume Nikki.
Spring
(Effect recommended to have before retrieving: none)
From The Nexus, enter Mushroom World. Travel west-southwest along the white pavement path, then take the northern path into a roughly elliptical area of mushrooms when you encounter an intersection (the southern path leads to a square of pavement with a broken vending machine next to a faceless man). Take the western path at the intersection inside of the ellipse, follow along the red cracks in the ground, and interact with the stemless mushroom cap with eyeballs. Then, pass through the eyeballs on stalks to enter the White Mushroom Field. Travel roughly southwest until you find a less saturated version of the stemless mushroom cap with eyeballs; interact with it to enter White Fern World. From the entry point, travel south along the path, take the eastern branch-off, and step on the black void to enter the Apartments. Head north past the faceless boy to reach the buildings, then enter the door on the second floor. Go up through the northern door, then go south and exit the room. From there, go west and get off of the porch of the building, then go through the transition point to the west of the building. After that, enter the door on the second floor of that building and go down the hole that has tentacles protruding from it. Once inside the long hallway, head east; the area will eventually transition. Keep going east until you see a monochrome creature with a red eye. Interact with the creature, then continue to the east until the area transitions again. Go through the double doors, head east a little further, then go up the stairs at the end of the hallway. Interact with the green-haired NPC to obtain the effect.
Holding down the interact key will make Urotsuki do a small hop. This effect can be used to jump up and reach otherwise inaccesible portions of some areas.
Invisible 
(Effects recommended to have before retrieving: Chainsaw, Rainbow or Lantern)
From The Nexus, enter Forest World. Travel due east of the entry point until your path is blocked by a line of trees, then interact with the white chocolate bar to enter Chocolate World. From there, travel south until you reach a four-way intersection, then go west at the intersection. Interact with the blinking, pink-and-purple, conical object to enter the Stone Maze. Head east until you encounter a dead end, then go north. At the first intersection, move east, then turn south at the subsequent intersection. Continue south until you encounter a red bowling ball; interact with it to enter the Bowling Zone. Go north from the entry point in the Lanes and interact with the three white pins at the top of the alley (make sure to avoid the purple bowling balls) to enter Bowling Pin World. Go northeast until you see a triangle of black dots surrounded by four pins, then step on the triangle of dots to return to the Lanes. Go north (ignore the opening to the other lane) until the map stops, weaving through the stationary obstacles as necessary, to reach The Invisible Maze. Navigate through the maze (you can equip the Rainbow effect and hold down the interact key to temporarily reveal the maze walls) and interact with the purple and yellow object. When you arrive at the seashore, go up to the NPC with the hat, equip the Chainsaw effect, and attack her (the area will desaturate). Interact with the purple and yellow object and backtrack through the Invisible Maze (it'll be visible this time). Once you exit the Invisible Maze, you'll appear in Yukata's area. This area is a non-linear maze; follow the direction in which Yukata is facing in each room until the area fades to black, even if you have to backtrack. After the area transitions, you'll appear on a glass platform above deep space. Follow the path of glass tiles until you reach a purple silhouette of Urotsuki; interact with the silhouette to obtain the effect.
This effect allows Urotsuki to become transparent, rendering her unseen by Chasers.
Cripple
(Effect recommended to have before retrieving: none)
From The Nexus, enter Marijuana Goddess World. Travel south and east along the goddess's body, then, once you reach the southernmost line of tiles, go due east until you find a cat's-mouth-shaped doorway set in a pink frame; pass through this doorway to enter the Dark Room. Head one room south from the entrance, take the doorway on the eastern wall, go up the stairway, then pass through the other doorway to enter the Sewers. Move along the path to the east, then head down the southern stairwell. Go west for the next two rooms, then use the ladder in the third room at the end of the path to enter Japan Town. Continue west into the town, then enter the alleyway located after the entrance to the hotel. Go directly east down the alleyway until the area transitions to enter a strange location with moving ladders. Once there, head north until you see Heishi-kun sitting in a circle of light from a streetlamp. Interact with him to obtain the effect.
Holding down the interact key makes Urotsuki say her "I can't do that" lines.
Stretch/Tall
(Effect recommended to have before retrieving: none)
From The Nexus, enter Graveyard World. Travel east-northeast until you find a vomiting heart, go through the heart's open mouth, then go through the door on the western wall of the room you're now in to enter the Hospital. Head west through the reception room, go through the opening on the west wall, pass through two segments of the hallway (you'll go by 6 doors), then enter the first door in the 3 hallway segment (door #7). Interact with the yellow, cycloptic snake wearing a boot to enter a monochrome maze of arrows. Navigate through the maze until you reach the blue creature at the northern wall of the maze, then interact with the creature to enter a odd room with a animated picture and a hanging girl. Go south from the entry point, turn east at the dark spot in the red line, continue east until you hit the wall, turn north and turn west down the green and red path next to the hanging girl, then pass through the rounded door frame at the end of the path to enter a large, laggy room filled with spinning glyphs and crystals. Interact with the small blue crystal at the southeast corner of the map, head northeast along the screen-sized blue map, and interact with the pink and red object to obtain the effect.
This effect doubles Urotsuki's height and halves her width, and it is required (in addition to some money) to enter The Baddies Bar.
Haniwa (Gyroid)
(Effect recommended to have before retrieving: none)
From The Nexus, enter Mushroom World. Go west until you find a path of white pavement, then move along the path in a northwesterly direction until you encounter a green teleporter. Interact with this teleporter to enter the Bug Maze. Travel west down the path until you are forced to turn north, then take the northeast path at the intersection. Follow the east path to the intersection, turn north at the intersection, then, once you reach the next intersection, turn east and follow the path to which the yellow arrow points. Interact with the monochrome sign at the end of the path to enter Sign World. Go directly south from the entry point until your path is blocked by a sign, then travel east until you find a heart. Move south-southeast from the heart until you find the Pyramid, then head south and then east until you reach the staircase at the front of the Pyramid. Travel up the staircase until it stops (the creature hopping around on the Pyramid should vanish), then walk back down the staircase to the front of the Pyramid. Travel to the southeastern corner of the Pyramid, then head northeast until you find a rectangular arrangement of stones. Interact with the center rock to enter the path to Haniwa Temple. Travel east along the path (interact with the haniwas on the path to clear the way) and go up the staircase until the map transitions. Continue east to the top of the stairwell; you'll be in Haniwa Temple once you reach the end of the staircase. Interact with the gray haniwa to obtain the effect.
This effect allows Urotsuki to move haniwa statues when the interact key is held down.
Cake
(Effect recommended to have before retrieving: none)
From The Nexus, enter Theatre World. Walk 7 steps south, then head due east until you find a grayish-brown archway. Pass through the archway to enter Cutlery World. Travel south until you reach the fence, hug the wall and travel west, then go south through the closest opening in the fence. Repeat these steps with the second fence. Once you reach the third layer, head east until you find a silver fork; interact with the fork, then travel west across the path and up the neck of the giant fork. Interact with the cake-headed girl in the yellow dress to obtain the effect.
Holding down the interact key makes the cake on Urotsuki's head drip frosting, which she wipes away.
Twintail
(Effects recommended to have before retrieving: Chainsaw, Telephone)
From The Nexus, enter Heart World. Head southwest from the entry point, then interact with the red pair of shoes on a pedastal to enter The Deciding Street. Go through the entrance underneath the red cover. Walk to the western end of the room, equip the Chainsaw effect, and attack the telephone. Then, equip the Telephone effect and stand on the gold-and-black tile where the telephone was sitting. After a while, the pink figure will walk over and "answer" Urotsuki, prompting a short cutscene in which you obtain the effect.
This effect is presently only cosmetic, though it can be combined with one of the costumes in the Dressing Room. Some of the sprites in the sprite sheet appear to indicate that this effect may have been designed to be used for combat or will be designed for such in future versions.
Child
(Effect recommended to have before retrieving: none)
From The Nexus, enter Mushroom World. Travel southeast until you reach a large square of white pavement, travel east for a few steps, then follow the pavement path that leads into a large ring of mushrooms. Travel west and north about the inner rim of the mushrooms, follow the path covered in red cracks, then interact with the stemless mushroom cap with eyeballs. Pass between the two eyeballs on stalks to enter the White Mushroom Field. Travel roughly southwest from the entry point until you find a less saturated version of the aforementioned mushroom cap; interact with it to enter White Fern World. Follow along the path, take the eastern branch-off, and step into the black space. Travel north past the faceless person, then enter the door on the second floor of the building. Move north and go through the door on the northern wall, then go south and exit the room. Head west along the porch, step off of the porch onto the snowy ground, go to the transition point to the west of the building, then enter the door on the first floor of the smaller building. Interact with the dark pink teleporter to enter The Docks. Navigate through the maze of the Docks until you reach the Submarine (you may wish to use the map on the Docks's wiki page). The Submarine only has a 1/8 chance of being open; if it's closed, retreat until the Submarine is a good ways out-of-sight, then go back and check again. Once the Submarine is open, enter the Submarine and wait for a while. It may be a few minutes before the Submarine reaches its destination, the Ocean Floor; you'll know that it's arrived when the sonar changes in pitch and the scrolling background changes in its scrolling speed [you can interact with the teal-haired NPC to make the Submarine transparent, which makes this easier to see]). When the Submarine arrives at the Ocean Floor, exit the Submarine, then traverse the area, keeping generally as close to the southern edge of the maps as you can (you should pass by various oversized object on the way). Once you find a northern path that leads to an open area with a bed in the center, take the western path and interact with the large egg-shaped object; this will bring you to a small room with a bed and a familiarly-patterned egg. Interact with this egg to obtain the effect.
This effect is cosmetic, shrinking down all of Urotsuki's proportions by a factor of 2. Holding down the interact key will make Urotsuki jump up and hit her head on an unseen object.
School Boy
(Effect recommended to have before retrieving: none)
From The Nexus, enter Mushroom World. Head west until you find a white pavement path, the follow the path in a northwesterly direction until you encounter a green teleporter. Interact with this teleporter to enter the Bug Maze. From the entry point, go down the west path until you are forced to turn north, then take the northeast trail at the intersection. Follow the path to the intersection, go north at the first intersection, then go west at the subsequent intersection. Go down the south branch-off from the west path, and step between the two humanoid figures to enter The Hand Hub. From that entry point, travel to the southmost peninsula of the Hub and interact with the portal there to enter the Blue Forest. Head west into the map, and continue west until you encounter a easel with a painting on it. Interact with this object to enter the Art Gallery. Go east from the entry point until you see a monochrome painting with what appears to be eyes on the left and right sides of the picture. Interact with this picture to warp to a black and white area with a ladder and a short trail to a pulsating cavern. Head east along the trail into this opening, then continue east along the long path past the somewhat disturbing background images. Eventually, you'll reach the end of the path, where a small pool of water rests. Interact with this pool to enter Monochrome Feudal Japan. Go southwest from the entry point until you reach a sort of dirt barrier, then go west alongside the dirt wall until it diverges to the southwest. Continue to follow along the wall to the southwest, then head east when the wall cuts to the east. Move through the opening in the southern wall when it comes up, then go roughly west-southwest until you encounter a fence with a substantial gap in it. Pass through it and continue south-southwest through the scattering of buildings. One of the open buildings leads to the area with the effect; the correct building will leads to a brief dark hallway between two brightly lit doorways. Go west through the hallway, then follow along the path until you encounter a blue-skinned NPC in dark clothing. Interact with him to obtain the effect.
This effect is cosmetic, and holding down the interact key will make Urotsuki flap her cape.
Trombone 
(Effect recommended to have before retrieving: Lantern)
From The Nexus, enter Geometry World. Go directly north from the entry point, then turn to the west once you one step to the north of a C-shaped line on the ground to your left. Continue west until you see a door framed in a large teal block. Head to the eastern side of the block, go northeast until you see a distorted green face, then go east one step to the north of the face. Continue east until you see a large opaque object similar to a signature; interact with the westernmost end of the signature to appear on Smokin' HAL. Walk down his cigar to the east, pass through his mouth (he'll turn blue and the background will become black), then walk back up his cigar to the west side of the screen to enter the Broken Faces Area. Walk to the west until you encounter a small hexagonal building with a UFO, then go a few steps north and look for the little green man walking from east to west. Interact with the man to enter The Baddies Bar. Once there, equip the Lantern effect and flourish the lamp; this opens all of the rooms that might possible contain the effect. Look around the area and enter all of the narrow black openings in the walls to look for the effect (be careful; most of these chambers contain Chasers). Interact with the multicolored flashing humanoid holding the trombone in one of the rooms to obtain the effect.
This effect allows Urotsuki to play in a duet with Elvis Masada. Holding down the interact key makes Urotsuki play a few notes on the instument.
Tissue 
(Effect recommended to have before retrieving: Motorcycle)
From The Nexus, enter Mushroom World. Go southeast from the entry point until you reach a large square of white pavement, then go up the north path that leads into the large ellipse of mushrooms. Go west and north along the inner rim of the mushroom ring, follow the path filled with red cracks, then interact with the stemless mushroom cap with eyeballs. Pass through the two eyeballs on stalks to enter the White Mushroom Field. Travel roughly southwest until you come across a desaturated version of the stemless mushroom cap; interact with it to enter White Fern World. Follow the path (ignore the branch-off to the east near the beginning) until you reach a large area shaped like an eyeball (NOTE: This path is extremely long. Usage of the Motorcycle effect is recommended). Once there, step inside of the middle square in the array of squares to the west of the entrance to enter the deepest section of this world. Travel approximately southeast until you encounter a cylindrical building. Enter the building, wait for the cutscene to finish, and interact with the white papery object sticking out of the building to obtain the effect.
This effect allows you to leave up to 5 markers (i.e., tissues) on the ground (hold down the interact key to do so), similarly to the Poop Hair effect from Yume Nikki.
Little Red Riding Hood 
(Effect recommended to have before retrieving: Motorcycle)
Go to Christmas World and interact with the smallest tree. Locate the manequin walking around in the Exibition and talk to him. In the nails area, locate the hexagonally shaped door. Enter it and go all the way to the end of the area. In the window room, make sure that the things in the window are bears. Once you are in the bear area, locate the telephone pole and interact with it. In the red and black area, find the black tube with the red eye and interact with it. From there, go left until you see 3 bleeding faces. Make sure you are left to the farthest left face and then go down. You should see a door with a space ship on it. Enter it and you will find yourself in a grey room with an odd creature and a UFO. If the UFO is not there, just exit the room and re enter it. Keep doing that until the UFO shows up. Enter the UFO. Go to the left door and enter it. Intaract with the computer on the left and select the apple option. You will hear a beeping sound. In the far right room in the UFO a clock will be counting down how long until you reach your destination. Once the clock hits zero, exit the UFO and go all the way down until you see a tree. Interact with the tree to get the effect.
The Red Riding Hood is simply cosmetic. It dresses Urotsuki up like the story book character Red Riding Hood.
Polygon 
(Effect recommended to have before retrieving: Motorcycle)
Go to the Grey Road from Red Streetlight World and cycle around the black areas. You should find a staircase leading underground. Go down it and keep traveling right until you come to a grassy area. Now go right until you come to a group of streetlights in a circle. Cycle upwards and interact with the small four-leafed shoot coming out of the ground. You'll be transported to the Warehouse.
Continue traveling right again through the area until you come to a white doorway on your left. When you enter it, you will be transported to a pinkish rooftop with a rotating triangle. Interact with it to get the Polygon effect.
The effect makes Urotsuki look like she is made of blocks, and if you press Z, a green outline will appear around her and her texture will become more detailed.
Pseudo Effects
This is a list of the effects that either cannot be collected, combinations of effects or are still in development.
Outfits
Dressing Room
Whenever you interact with the manequins with outfits on in the Dressing Room, your outfit changes. You can also wear the Glasses effect with the suit and the Twintails effect with the maid outfit.
Swimsuit 
If you go to the hot springs from the Mini Maze in Toy World, Urotsuki's outfit changes into a blue swimsuit with a light blue swim cap.
Santa Claus 
In Christmas World (accessible from the Hand Hub), go into the large house and chainsaw the man wearing a Christmas hat. Interact with the hat and your outfit changes to a Santa Claus costume.
Combo Effects
Wolf/Motorcycle 
This is the only combo effect currently programmed in the game. By selecting the Wolf effect and then the Motorcycle, you are able to ride the motorcycle as a wolf.
School Boy/Glasses File:Policemask.png
There are currently only two sprites of this effect available on the sprite sheets, but it looks like you have a sheet of paper in front of your face with a drawing of glasses and a mustache on it (a disguise?).
Bug/Rainbow, Chainsaw,??? 
These Bug combos are available in the Debug Mode of the game. Using Rainbow with Bug makes you into a rainbow-colored bug, using (possibly) Chainsaw and Bug makes you a bee, and using Bug with an unknown effect makes you a green beetle.
School Boy/Bike
Only available on a sprite sheet currently. It's basically Urotsuki with the School Boy effect riding the bike.
In Development
Block Person 
This can transform you into a walking block from Toy World included in past versions of the game. You are able to get this from the E tile somewhere in Toy World, but its abilities are unknown.
Bat
This effect gives Urotsuki bat wings. This is also obtainable from the E tile in Toy World, yet it is only cosmetic for the time being.
Odorika 
This effect makes you look like Odorika, and seems to be only cosmetic. This is currently only available on a sprite sheet.