There is only one rule:
Light all eight candles.

Explore a maze-like area and find all eight candles to light them.

Each time you return to the title screen, the candle locations will be randomized, offering a new challenge.

This game contains horror elements and jump scares.
Some events require audio cues, playing with speakers or headphones is recommended.

More details on the official game page of Yatsuakari ...