In front of you is a pile of objects. Your aim is to remove them one by one without disturbing the red blocks. If you are smart, and somewhat lucky, you will remove all the objects and receive a new pile to work with. The more objects you remove in sequence, the faster your score increases.
If you reach the point where no further objects can be removed without disturbing a red block, you may opt out of the screen and move on to a new one.
The point is - if you know what you are doing, you may play for quite a while. You may, theoretically, play forever. But don't let your attention wander for a moment. At some point, no matter how smart you are, your game will come tumbling down....