There are 28 Coins to be collected throughout the various locations in the dream world. These are tracked by a counter on your save menu, and each one will unlock a new painting in the Empty Museum.
All 28 coins are collectible without obtaining any Memories except for the Bubblegum.
#1
Location: Found in the Memory Room during the game's tutorial.
#2
Location: Found in First Steps, near the stairs to the north.
#3
Location: Found to the south of the entrance in Particle World.
#4
Location: Found in Puzzle Chamber after solving its secret puzzle.
#5
Location: Found on a small platform in Lamp World.
#6
Location: Found in SUGAR by a large candy cane and some strawberries.
#7
Location: Found in Unicorn Woods, either west of the arcade machine, or as a reward for slaying every unicorn.
#8
Location: Found in Flower Field by a red sunflower.
#9
Location: Found in a deeper section of the Orange Mausoleum.
#10
Location: Found in Cave Game, either in the second room from Monochrome Building, or in the same room as the Winged Boots memory.
#11
Location: Found in R-Maze, randomly placed on later floors.
#12
Location: Found in Flesh n' Blood, on the landmass with teeth.
#13
Location: Found in a section of Weird Forest.
#14
Location: Found in Windy Canyon, east of the moon cave.
#15
Location: Found in Upper Totem Hill, north of the entrance to Thorny Vine World.
#16
Location: Found in Realm of the Orb, in the southwest of the green section.
#17
Location: Found in Isle of Seasons by going inside the house during winter.
#18
Location: Found in Sunset Cliff lying on the grass.
#19
Location: Found in the dark version of Yin Yang Lake, south of the entrance from Block Galaxy B.
#20
Location: Found on a dark cloud in Above the Clouds reachable by going southwest of the entrance.
#21
Location: Found in Swimming Pool inside the fourth changing room.
#22
Location: Found in Overgrown Rust in a walled-off section southwest of the entrance to Blue Flow.
#23
Location: Found in Blue Flow to the northwest.
#24
Location: Found in Neon Zone in the yellow section.
#25
Location: Found in Rainforest Road by the lockers.
#26
Location: Found in the easternmost room within the Decrepit Facility.
#27
Location: Found in Block Galaxy, by the shortcut ladder to Block Galaxy B.
#28
Location: Found by a large fruit in Thorny Vine World.
Trivia
- Collecting all 28 coins without any Memories except for the Bubblegum will cause text to appear on the rock in First Steps.