Domino Cascade

Domino Cascade is a blank table and an unlimited supply of dominoes. You drag a finger or cursor and dominoes drop into place behind it at even spacing, following whatever curve your hand made. Loop it, spiral it, run it into a tight zigzag — the spacing stays constant regardless of how fast you draw, so a quick flick produces the same evenly laid chain as a slow careful stroke. Then you tap the end of the line and the wave sets off.

The toppling is simulated as an inverted pendulum rather than a scripted animation. Each domino starts leaning slowly, accelerates as its angle increases, and only tips the next one once it has actually fallen far enough to reach it — the trigger angle is calculated from the spacing and the domino height rather than being a fixed guess. That means a chain laid slightly too loose genuinely stalls, and a tight chain runs faster than a loose one, exactly as real dominoes do.

Each domino draws its top face separately from its body, and that face shrinks as the piece goes down, which is what gives a flat two-dimensional canvas a convincing sense of height. The colour walks around the spectrum along the chain, so a long run topples as a travelling rainbow. You can tap anywhere in the middle of a line to start the wave from there instead of the end, or lay several separate chains and set them off one after another. Free, browser-based, nothing to install.