On the left, you see a grid of jumbled up balls. On the right, you see your target formation. Your task is simple: Make the left look like the right. This is done by rotating clusters of four balls (with your mouse or the [Arrow Keys]/[Space Bar] combo), similar to Bejeweled Twist. It doesn't matter which ball goes in which spot, so long as the colors match. Once you match the image, you're on to the next puzzle.
There are forty patterns to solve, which increase in size and complexity as you go along (such as adding in more colors). Once you figure out the techniques to manipulate the balls in the way that you want, solving the levels is pretty easy. However, the real challenge lies in trying to meet (or beat) the developer's target number of moves. For most levels, the target is 4-8 moves, but can you plan ahead to meet the goal on your first try? Can you conquer the tasks with brute force and trial and error?
Analysis: What makes Spin-n-Match interesting is that at the heart of a very simple game, you have two possible levels of difficulty. You can try to simply beat all forty levels, which can be tricky enough when you're struggling to figure out the best way to switch two misplaced balls without ruining the rest of your progress. If that's too easy, then you can go for the developer's target scores, a task which could drive you batty.
Either way, Spin-n-Match is a nifty little puzzler that'll keep your head spinning. (Fifty bucks says you saw that coming.)