This 2D companion to the 3D Rube Goldberg machine draws the same chain-reaction idea as a flat, physically-simulated side view: a ball rolls down a ramp under gravity and friction, strikes a domino whose fall is governed by the physical-pendulum equation, the domino's tip hands angular momentum to a see-saw lever whose unequal arm lengths trade force for launch speed (real mechanical advantage), the flung ball follows a true projectile arc into a bucket, and the bucket's tip releases a final ball that free-falls onto the target. Press Start to release the chain, adjust the stage-speed slider to slow down or speed up whichever stage is currently playing, and watch the live stage name, elapsed time and progress bar track the reaction from first ball to final impact.