Indivisible is an NES homebrew demake of the RPG/Metroidvania hybrid PC game of the same name. As this game is more of a proof-of-concept than a full-on demake, it lacks the RPG mechanics of the original. Nevertheless, the essential parts of the story are still intact, and the game comes with very well-flowing graphics even for a homebrew NES game.
FractalFusion opts to complete the game to "Clearest!" as fast as possible. "Clearest!" is basically completing it at 100%, which requires defeating the secret boss,