Video: Time for another dumb yet compelling sketchpad-physics computer game

Not as ethereal as “Crayon Physics Deluxe” but the wonderment factor is still there. What is it that makes these dopey simulations so hypnotic? Is it that they poignantly fulfill some secret vestigial wish to see one’s childhood drawings spring magically to life? Or, per my own theory, is it just the pretty colors and funny shapes?