Mask v1
A snake of colour-cycling blobs crawls across black while a roaming outlined window swaps everything inside it for a chunky pixelated copy.
A segmented trail of overlapping circles worms through the frame, its colours sliding between teal, orange and magenta as it moves. Over it wanders a thin blue rectangle the size of the canvas: inside its bounds the scene turns into coarse mosaic blocks, outside it stays sharp — on the cover a single crisp red blob pokes out just below the boundary.
The trail is drawn twice each frame: once onto the main canvas and once into a buffer running at one-twentieth pixel density, which is all the pixelation is. A mask following a sine/cosine path composites the low-res copy only inside the roaming window, so the censor square drifts over the scene rather than the scene changing. The trail's own colour never comes from a palette — each channel rides its own sine or cosine phase, so the hue keeps circling.
