This is the classic mechanical maze and marble toy game brought up to the iPhone times.
There are concentric rings with a single entrance between each ring and the next. There is a set of 12 marbles(ornaments)
The objective is to tilt the iphone in different directions so as to roll the marble in the desired direction - the effects of gravity will roll the marble when the iphone is tilted. Continuous smooth manipulation is required to move the marble in the right direction.
You will need to be deft and maneuver the marble at the right angle and speed to get it through circles and gather all of them at the center of the maze. Note that if they are rolling along edge touching a ring, the movement maybe different from what you expect although it is physically correct.