You would be surprised to find that the game actually has a background story and is following a plot. You will be trying to survive and win the game by simply avoiding attacks and surviving until the song has finished playing. To make things even more challenging, players are not allowed to fight back and defend themselves.
The livelier the songs, the more erratic and unpredictable these projectile objects will be and of course, the harder they are to evade. The movements of these obstacles are based on the music that is playing so if you are listening to an upbeat tune, expect everything to be fast-paced.