First impression
The first thing I noticed when I started the game was the liberal use of color. The author does an excellent job of creating a gaming environment that's pleasant to look at, without being distracting, as you can see in Figure A.

FIGURE A

Here's the Herdin CatZ startup screen.

The first thing you do is choose whether you want to start a new game, continue a previous game, or change the options. I jumped right into a game. Once you tap "New," you're presented with a brief description of the situation and what you must do. As I started playing the game, I was slightly disappointed that it wasn't more difficult. I raced through each of the five levels in the first world without losing a single cat. I suppose the game may have been designed this way to give you a chance to learn how the game works. But, by the time I was done, it felt a little monotonous. The second world, however, was more difficult, and I invested much more time (and several cats) in completing it.

Overview
Herdin CatZ consists of five worlds: Tree world, Bug world, Fish world, Yarn world, and Cheese world. The route between each of the five worlds is pictured in Figure B.

FIGURE B

You'll have to navigate your cats through each of the five worlds.

Each world has a different variation of five levels that must be completed before moving to the next world, and each world is progressively more difficult than one before. You start each world with three cats. If you fail to accomplish the objective of a given level, you lose a cat and have to start the level over. If you lose all three cats, you must start the whole world over.

Corral Craze
The object of the Corral Craze level, pictured in Figure C, is to herd at least five cats through the gate of the corral.

FIGURE C

Herd the cats through the gate before time runs out!

You do this by using your stylus to encourage the cats to move in the direction of the gate. Of course, the cats have no interest in this and wander around everywhere except the gate. There is a door in the lower right-hand corner that the cats try to escape through. If enough cats escape through the door, you lose. If the timer runs out, you lose. If you manage to get enough cats through the gate, you progress to the next level.