The puzzles are nicely decorated, and the animation is faultless. A few good sound effects.
Shame there's no background music.
Puzzle fans only. A version 1.1 patch is available. Manual written in entertaining, Leonardo-esque language. Uses standard Windows menus. In Marble Drop, you send some poor, innocent marbles who've done nothing to hurt anyone in their quiet, spherical life and send them on a helter-skelter journey around devious contraptions.