Zuma's Revenge is, of course, the sequel to Zuma, PopCap Games's hit puzzler about a frog that spits balls of different colors to match three or more in a sequence. Why a frog? I'll never know. But the gameplay itself happens to be fiendishly addictive, as so many PopCap games are.

It's a race against the clock, as a multitude of colored balls -- red, yellow, blue, and green -- roll along a track toward the endpoint. If the balls get there, it's Game Over. If you fire a ball of a given color so that it creates a line of three or more in a row, these balls disappear, leaving a gap in the line. While the gap exists, the stranded balls remain stationary and can be picked off easily. It's the moving line of balls that provides the challenge -- numerous times I fired a ball off, only to miss its target color and get mixed in with other colors, which makes it much more difficult to line up three or more.

When you remove a number of balls, the gap is filled by the two lines of balls coming back together. If the two lines feature balls of the same color as their bookends, you'll get a combo bonus. Chaining combos will also get you points, and any unused track gets you more bonus points still. Also, making a match in a distant part of the line that forces you to shoot between the gap gives yet another bonus.

Fortunately, there is help in the form of powerups. Random balls will turn into powerups at random times. If you make a match with one of these balls in it, you'll gain that powerup. The powerups are, in no particular order:

Star: This ball will fill in a portion of the Zuma Bar at the top of the screen. When the Bar is full, new balls will stop rolling out, effectively immobilizing the line for a short time. You can also shoot fruit to fill the bar, but this is more difficult, as fruits lay outside the line, meaning you have to clear a space between balls to hit the fruit.

Reverse: As expected, this powerup turns back the normal direction of the balls for a short duration. You can imagine how helpful this is.

Slowdown: Another self-explanatory effect, this lasts for a short time, reducing the speed at which the line advances toward its terminal point.

Accuracy: This powerup paints a line issuing forth from the frog, making it much easier to target and hit distant balls.

Tri-shot: This powerup fires three black balls in a spreading pattern, destroying all balls in their path.

Lightning: This powerup destroys all balls of the target color.

Laser: This zaps balls and fruit with pinpoint accuracy.

Zuma's Revenge is horribly addictive. I'm kind of upset about it. You can grab the demo right here on Big Download for both Mac and PC.