A checkerboard world where flat scenes replace each other by conveyor. Three times a loop every row slides by exactly one screen width, each row starting a beat after the one above it — so the next scene rides in from the edge, seam and all, and the rows shearing against each other while mid-flight are the whole undulation.
Nothing on screen is ever recoloured mid-flight. What reads as colour sweeping across the board is the seam between two scenes passing at peak velocity — during a pulse each row is simply the current scene’s row and the next one laid end to end. The one true recolour is the palette change, which fires only while every row is at rest and crossfades the whole board at once.