Spiked Circle

This game's goal is for star to change orbit to avoid spike.
There is universe which is full of twinkling stars.
There is circle in the center.
There is small star which is rotating on the circle.
By the way, spikes apprear on the inner circle or outer circle.
Small star must rotate on  this circle without colliding with these spikes.
If touch any where on the screen, star move onto inner circle or outer circle in a toggle way.
Touch on screen well to avoid spikes.
Help star to rotate on circle well.
Compare your score with other's in global leaderboard.