Cheat:

Warning: allways make a backup before editing your registry.

Activate secret persons:
To activate Burn, Keith, og Wong (from teh original Psychic Force), open windows's regedit (REGEDIT.EXE) and go to this adress:

HKEY_CURRENT_USER/Software/TAITO/PF2012/SpFlags

Here you set the values for 'Burn', 'Keith', and 'Wong' to 1.