Draw with the mouse to create sand, smoke, fire or water. A cellular automaton simulates gravity, diffusion and combustion in real time. Materials interact — fire ignites wood, water extinguishes fire.
Each cell updates based on its neighbours: sand falls with gravity, smoke rises and diffuses, fire spreads to adjacent combustible cells, water flows and pools.
Select a material (sand, smoke, fire, water, wood) and draw. Watch interactions: fire + wood = smoke, water + fire = steam. Clear to restart.
This type of "falling sand" game was popularised by the 2005 Java applet "Hell of Sand" and inspired commercial games like Noita (2020), which builds entire worlds on pixel-level physics.