Beat the Almighty and save your game load it back up and where the bosses were before there will be a black crystal to open and fight the boss again.
Easy leveling
Make sure you have unlocked the level "Ancient Path Of Death" and select level 51-70. Also, make sure you have the gene command "Absolute Zero": just use it in pairs and see that all your hits make a "BlowOut".
Final Ending
Beat Almighty with 4 couple.
New Game +
Finish the game with any character. When you start a new game, you'll retain all stats, items, and money.
New title screen
Defeat Piu Piu with all characters to unlock a new title screen.
New title screen
Defeat Piu Piu with all characters to unlock a new title screen.
Other Characters
Beat the game once. DO NOT START A NEW GAME. Just load the old one again and a new map will be open go through it and defeat the Almighty and save at the end. When you turn it back on the character select screen will have arrows at the bottom to switch between the characters.
Unlockable
How to Unlock
Ayuta and Mana
Beat the Almighty
Olgar and Vhati
Beat the Almighty
Rematch
Once you beat The Almighty you can reload your save and use the black crystal to fight bosses again.