Circuit Swap is a deceptively simple little game for the iPod Touch, iPhone and iPad. I personally played on my trusty iPod Touch.

In the most basic terms, you have to plug batteries into the appropriate sockets to light up a little cityscape. You have a small board (4x4 grid) and need merely to move the battery across the screen into the socket — ideally in the fewest moves possible. That would be easy, if not for the twists — and therein lays the challenge.

There are three different kinds of batteries. Some can move only vertically. Some can move only horizontally. And finally, some can move either horizontally or vertically. There are, of course, special squares on the board that mix things up. The switch block changes the orientation of a battery with a specific move direction. The teleport blocks come in pairs — enter one teleport, and exit from its twin. The barricade block is just there to get in your way. The synthesis block is an interesting critter. You activate it by moving a battery onto it, and then it has one of the other block powers after that. The battery, sadly, is consumed in the process. Watch out, though — on some levels, the synthesis block is a trap. Finally, there’s the socket block — the destination of your valiant little battery.

The game starts with 20 levels available. Once you’ve completed level 20, you open up the second screen, containing levels 21 through 40. Most levels just require that you get the battery (or batteries) into the socket(s) as efficiently as possible. Every five levels, this changes, and you have a timed challenge. I found the timed mode to be brutal. I like to think about my moves, and that’s tough when the clock is ticking down to failure.

You can earn trophies as you play. I didn’t really didn’t pay much attention to them, but they’re worth thinking about. Get enough trophies for superb or perfect levels, and you open up five additional levels, and I’m told this is the area in which the developers will be adding additional free content. So far, my driving priority is trying to achieve the minimum moves to accomplish the level, but I expect that will change when I get near the end level. I can’t tell you how many times I’ve played a level over, just because I was two or three moves from optimum. The game can be addictive that way.

I really enjoy Circuit Swap. It’s easy to learn and a satisfying challenge to master. At just under a $1, it’s an excellent value and fun addition to your portable gaming library.