Bonus levels are levels that are added between two old levels. Its purpose is to let players collect keys and to let players have a chance to practice before going on to the next official level. The secondary theme of each bonus level is the same theme as the main theme of the next level. Currently there is one bonus level: Illusion. Then the second bonus level, Monody cames after Christmas.Candy,the third bonus level, cames this year February.8-Bits is fourth bonus level that cames at Easter.Matrix is also a bonus level,but with Level 17:Cube's Reversed Music.It cames on May.Joker,the 6th bonus level only cames on June like Level 19:Reggae.The 7th bonus level Mental Rave cames on August.