geoSpark is based around an idea so simple that it reminded us a little bit of our days in Kindergarten. While “round blocks in round holes, square blocks in square holes” might oversimplify things a tad, the game is all about keeping like shapes together and different shapes apart…. in space …with your finger.

As the game begins you’ll find a number of neon shapes are floating around a spacey-background, accompanied by some catchy piano-based electronica soundtrack. If the game were to be glanced at by a passer-b, they might think you were fiddling with a music visualizer – the kind you might find in iTunes or another popular media player. But we assure you, geoSpark is no music visualizer.

As these shapes float around the screen their paths will sometimes cross. If they cross too close they’ll get into each other orbit and eventually crash into one another, causing an explosion and ending the game. This is where you come in. Your job is to remove all of the shapes from the screen before an accidental collision occurs, thereby saving the day and racking up a killer high score.

To remove the shapes, all you’ll need to do is touch them. Sound simple enough, doesn’t it? But just touching the shapes isn’t going to do much for your score, so you’ll need to learn a few tricks to string together combos. To get a combo going, you’ll touch a shape and draw lines to connect it to other shapes without lifting your finger. The more shapes you can get in one combo, the higher your combo score will climb.

As you make combos the gravity around your finger gets stronger — the higher your combo, the stronger the gravity. While eliminating 10 identical shapes without ever lifting your finger may do wonders for your score, this means all of the other shapes are going to be drawn towards the orbit around your fingertip. The trick in geoSpark is balancing these massive combos while making sure you never hold your finger to the touch screen so long that all of the other shapes converge on you and trigger a massive game-ending explosion.

In addition to combos and shapes, there are a few special items you’ll need to know about to make the best of your geoSpark experience. Sometimes a multiplier shape will come through. Adding that to any part of a combo will increase your score for that one combo by whatever number is in the center of the shape. There’s also a strange shape that looks a little like the old CBC logo (Canadian readers know what I’m talking about) that will eliminate every shape from the screen that doesn’t match the one you’re trying to combo together. Little additions like this really helped to flesh out the offering and make it more than a simple one trick pony.

For those who like their gaming to take on a more social aspect, geoSpark takes advantage of the OpenFeint social gaming platform. OpenFeint lets you keep track of your friends, what they’re playing, and how they’re performing in each game. You’ll be able to see exactly how well you’re doing compared to your friends thanks to OpenFeint’s game-specific leaderboards. OpenFeint also supports an achievement system, but we were disappointed to see that geoSpark didn’t choose to participate in that.

geoSpark is fun, frantic, and fast. In a lot of ways, it’s exactly the sort of experience the iPhone was made for. Getting a simple game so right means there’s very little to find fault with – in fact our only nitpick was with the lack of multi-touch gameplay. Since the iPhone can recognize more than one finger at a time, it would have been awesome to use a second finger to deal with different shapes while you were stringing together combos. Still – it’s a small complaint to have in the face of such a top notch experience.

A lot of people thought it strange that Critical Thought Games, a company known for their tower defense gamesgeoDefenseandgeoDefense Swarmwould take theirgeoseries in such a completely different direction. Clearly, they knew what they were doing. geoSpark is everything a quick-play iPhone title should be: simple, addictive, and refreshingly fun. Each game might only last a few minutes, yet geoSpark is almost impossible to put down. For 99 cents, you really can’t go wrong.