Finish the game on Normal difficulty.
Finish the game on Hard difficulty.
Beat Super Hard difficulty.
Spend crystals between stages during the campaign or clear time attack. As data completion increases, new characters are unlocked. Default - Enn Default - Hyu Default - Ray #1 - Goblin #2 - Dylan #3 - Soldier #4 - Cyclops #5 - Goblin Tank #6 - Sorcerer #7 - Roper #8 - Han #9 - Heavy Gear #10 - Gargoyle #11 - Edo #12 - Sky Knight #13 - Valgar #14 - Zur #15 - Cerena #16 - Nicole #17 - Kanon
Finish Time Attack mode multiple times to unlock new characters or donate gems in story mode to the laboratory.
Beat the game on Super Hard difficulty.