The theme of Casual Gameplay Design Competition #4 was "ball physics", and you can tell that Monsterkodi (author of the excellent 3D puzzle game Kiki the Nano Bot) was taking it seriously. So very, very seriously. You see, in Koogel, you're using six medium-sized balls to indirectly manipulate a bevy of smaller balls, in order to light up a collection of even smaller balls. This all takes place on the surface of one huge ball, displayed on a screen you are watching with your eye-balls. Meanwhile, you're living on a giant ball named Earth, which is rotating around the Sun, which is also a ball. You might even be having a ball, or be tempted to bawl, like Lucille Ball. It's enough to make your head explode, man. And if your head (which is shaped kind of like a ball) is still in one piece now, it will surely detonate when you try to process Koogel's instruction screens, which are written like the directions for assembling your own NASA satellite.
No sir, Koogel's rules are not very intuitive, and the visual layout doesn't help. Every entity in the game is a mono-colored sphere, and the three numbers in the corners of the screen don't tell you anything about your goals. You could be playing an episode of Talk to the Abstract Wart-Headed Creature and it would look exactly the same. But there's an intriguing game of color-matching skill hiding behind Koogel's poker-faced exterior, and it's worth getting into, so I'm going to spend most of my time here just explaining how it works.
You control the Koogel, a screen-sized sphere festooned with smaller spheres of various purposes. Six large spheres of different colors are distributed equally around its surface. The position of the mouse pointer controls the Koogel's rotation, and that's how you move the big spheres around. There are also a number of smaller spheres which you must knock about with the big spheres in order to meet the goals of each level. The small spheres move independently of the rotation of the Koogel, and they can't move around to its back side, where you wouldn't be able to see them. If one is about to travel out of sight, it instead bounces off an invisible boundary and returns to the play field.
The game rotates through three different types of level, which the Koogel will indicate by turning three different colors. The three variations have totally different rules, so I'll explain each in detail. I'm putting these guidelines in spoiler tags, so if you want to play around with it yourself, or try to puzzle things out with the in-game instructions, you can skip right over them.
Your goal here is to link all the small spheres together. They will only link up if two of the same color touch. If you hit one with a big sphere, it will change to the big sphere's color. On the first gray level, all you have to do is make the two small spheres the same color (any color will do) and knock them into each other. On higher levels, it gets more complicated, because only the spheres on the end of a chain can form new links. Once all the small spheres are united in a single chain, you win the level.
If two small spheres of different colors collide, both of them will change color, according to a consistent system. A red ball will always turn blue, a blue ball will turn gray, and so on. The cycle is Red, Blue, Gray, Yellow, Purple, White, and then back to Red. But it might as well be random when you first start playing, because it's almost impossible to remember, and there's no on-screen reminder. If you're trying to pass the level with a low hit score (the number in the lower left keeps track of how many times you hit a small ball with a big ball) then the color order is important, but if you're just trying to pass levels, it doesn't really matter.
Your goal is to light up all the little gray dots between the large spheres. For example, if there's an unlit dot between the yellow sphere and the blue sphere, you need to first hit a small sphere with the yellow sphere, then with the blue sphere. Then the dot will light up so long as the small sphere was blue when the large blue sphere touched it.
Each time you hit a small sphere with a big sphere, the small sphere changes color, according to the same rotating system as in the gray levels. So if you need a particular dot to light up, you may need to hit a small sphere several times with your first large sphere until it's the same color as the second large sphere. Once all the little dots are lit, you win the level.
Again, your goal is to light up all the dots. The gameplay mechanic here is sort of a combination of the other two levels. When two differently colored small spheres touch, they bond together, and then light up a dot between the two appropriate large spheres. For instance, if a red small sphere links up with a black small sphere, the dot between the red big sphere and the black big sphere will light. Change the small sphere's colors by hitting them with the big spheres just like in the gray levels.
Dots only light up when you form new links. So usually, you'll have to break the small spheres apart a few times, which you can do by hitting them with other small spheres of the same color. If all your small spheres are already linked together in formation, you can separate them by smashing them against the invisible horizon of the Koogel.
Analysis: The fact that it took so long to write those rules out (and that it probably didn't clear things up at all) is an indication that playing Koogel isn't a matter of instinct. The goals, gameplay, controls, and interactions are all very cerebral. You won't succeed at this game by just moving stuff around randomly, no matter how much you try, and that's seldom good for a casual game.
That's especially unfortunate because Koogel can be quite absorbing, once you understand it. You're always in direct control of six moving objects, keeping track of a dizzying number of variables and vectors, and eventually it all feels miraculously natural. But the learning curve is painfully sharp for what is essentially just a simple game with really solid physics and a unique premise. To make this work for more people, there would need to be a straightforward and visual tutorial, and much more helpful on-screen indicators. There especially should be a clear reminder of the color cycle that's so important on the red stages.
I would suggest a total overhaul of the visual presentation, except there's nothing exactly wrong with the minimalist look it has now. It's just unfriendly and distancing, which means that a lot of players didn't take the time to get to know this entry when the contest was going on. Give it another try. At worst, it will be just as confusing as the first time around, and at best, you'll discover a new and fascinating test of hand-eye co-ordination. It tickles a part of my brain that nothing else ever has, and that's enough for me to recommend it wholeheartedly.