The objective of Zuma Revenge is to eliminate all of the balls rolling around the screen along a given path, with other balls (the path is clearly visible in all of the levels except the last level), before these balls reach the evil green dragon structure, which will open to varying degrees as a warning of oncoming balls.
The player can carry one ball at a time. To prevent the balls reaching the green Dragon, the player can eliminate the balls by firing a colored ball from the stone frog idols 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.
There are bonuses for collecting points (usually through gaps) giving you a black ball that can destroy different collored balls between the target exploding the balls in a chain reaction.
Azuma revenge is an incredible game created in Unity and available on IOS.