Marble Drop is a puzzle video game published by Maxis on February 28, 1997.

These marbles are picked up and dropped by the players into funnels leading to a series of rails, switches, traps and other devices which grow more complex as the game progresses.

When a marble runs over certain sections of the puzzle, the paths may be rerouted or cut off, either temporarily or permanently.

These explanatory notes are a part of the background, informing the player of new pieces of equipment and their effects.

Black marbles are very expensive, but change to the correct color when they arrive in a bin.