Hidden Ending Sequence (XMultiply)
Hold C after defeating the last Boss.

Level Select
At the Title screen, hold L + R + Start.

All Weapons (XMultiply)
Press A + C + X + Z to pause game play. Then press Left or Right to select a new weapon.

All Weapons (Image Fight)
Press A + C + X + Z to pause game play. Then press L or R to select a new weapon