Gameplay :
The objective of ZDC is to eliminate all of the balls rolling around the screen along a given path (the path is clearly visible in all of the levels except for the last level) with other balls before these balls reach the yellow skull structure, which will open to varying degrees as a warning of oncoming balls. The player can carry two balls at a time and can switch at any time. As soon as one ball reaches the skull, the others follow and the player loses a life. To prevent the balls from reaching the skull, the player can eliminate the balls by firing a colored ball from the stone frog idol's mouth towards the chain of balls that will continue to push forward until the player fills the yellow bar, which is when the balls will stop producing off-screen. When three or more of the same color come in contact, they explode, possibly triggering other explosions as part of a chain reaction. The level is completed when after the bar is filled, the player eliminates all of the balls on the screen.