A call to action sitting in a pit of two hundred and fifty shapes that behave like a coarse fluid. Each pair inside the spacing radius pushes apart, blends velocity toward their average, and raises a density count on both; that count then softens gravity, damping, and the separation correction for the frame, which is what keeps a settled pile from boiling. Neighbour lookups go through a spatial hash rebuilt every frame, so the pair test stays local rather than quadratic. Press and drag to inject pointer velocity into anything within range. Canvas 2D with no physics library.