and the symbol for infinity. Some levels are closed tubes that allow the player to loop throughout it continuously, while others have definite left and right endpoints. When all sixteen levels have been played, the sequence repeats with a different color scheme and higher difficulty. One set of levels (65 through 80) is "invisible" (black). After reaching Stage 99, the level counter stops increasing and each successive level shape is picked randomly.

Enemies first appear on the screen as swirling