This game made me want to cry, i love you game.
Abraxxas848d at the top left side there is a sort of journal thing, every time when you find a clue, it's saved there, the different clues are in different colors, there are always free clues that you can get, check which one's you need. Don't forget to interact with everything.
They call them lightbugs, they have red ones in the desert and green ones in the north. They live on the same continent, so yeah, they're connected.