In CHALLENGE MODE you can fight hidden bosses, visit new stages and and have fun with competent missions. This is the best way to take advantage of Infinos Gaiden once you have completed it.

Unlockable	How to Unlock
BOSS ATTACK	Complete all the previous challenges.
EX STAGE	Unlock and beat the EX STAGE (secret level) during the game.
LEGEND MODE (ALL-STAGE)	Complete the BOSS ATTACK Challenge.
SIN EXTRA STAGE	This is the final challenge and the hardest. Complete the SPECIAL STAGE 3 Challenge.
SPECIAL STAGE 1	Complete the LEGEND MODE (ALL-STAGE) Challenge.
SPECIAL STAGE 2	Complete the SPECIAL STAGE 1 Challenge.
SPECIAL STAGE 3	Complete the SPECIAL STAGE 2 Challenge.
STAGES 1-7	Finish these levels in the game to unlock them.