Hey there. If you click the black box with the white '?' it will tell you what to do to unlock their gallery. For Fairy gallery to unlock 100%, 4 essence is required. There is a debug option to collect all essence from all predators, though you will need to have the fairy with you for that fairy to take credit and unlock it this way.
Next update will not have sounds. Adding sounds is somewhat on my radar, but I can't guarantee it will be added at all.