Zuma is an extremely simple, and it has to be said, extremely addictive game that even got someone like me, who avoids puzzle games like the plague, quite addicted.
You control a small frog in some kind of ancient Aztec world that revolves on an axis. The frog spits out different colored balls that destroy other balls that are whirling around the frog on their way to the center to access a sacred golden skull. It's your job to make sure that the frog spits out enough balls to destroy the balls that are aiming towards the golden skull before you get there.
The catch is that the balls are three different colors - red, green and yellow. You can spit out balls of the corresponding colors but only one at a time. When three balls or more are lined up in a row, if you hit anyone of those balls with a ball of the same color, the balls disappear and you earn points. You can sometimes change the color of the ball you are gong to spit by clicking the right mouse button - hit the left button to fire.
Zuma has two modes - Adventure and Gauntlet although it's hard to say what's the difference between the two. Both modes have the same gameplay, funky tribal soundtrack and great graphics and sound. It's deceptively addictive once you get going, and quite therapeutic as you watch the balls gradually blown away. The downside is, it's probably bit too easy as the balls move rather slowly.
Zuma is a great game that will appeal to both adults and children although note that in this trial version, you're limited to 60 minutes of play.