This is a very simple, yet quite challenging puzzle game. It’s all about not loosing your marbles.
There are blue and pinkish-red marbles that are coming out of the sides of the green board, and you need to maneuver them. If two marbles of different color collide, the green square they were on at the moment will vanish – uncovering a Black hole and all the latter marbles might fall through it. However, if two marbles of the same color collide, they form a brick.
Now these bricks are the things you actually need. You need to stack them up in order to raise your level bar (on the left of the screen) and in order to collect bricks you need to hit them with a marble of the other color. Such a marble will collect the brick and keep moving on in the same direction, while a marble of the same color as the brick will simply deflect starting moving in the opposite direction.
The only thing you have to control the marbles are the \\ and // tiles you can place on any green square if there is no marble currently on it and the marble will make a 90 degree turn in the given direction.
And that’s about it. Like I said, simple, yet fun and quite addictive. A solid game that might be just the right thing for a short coffee break. Definitely worth a try!