Each included game uses a side-view perspective and sends the player through a sprawling castle rather than a strictly linear stage sequence. Players explore rooms, defeat enemies, collect weapons or equipment, locate keys and relics, and defeat bosses to open new routes.

Circle of the Moon uses Nathan Graves and its DSS card combinations, while Harmony of Dissonance uses Juste Belmont, spell books, relics, and equipment. Both games improve the protagonist through levels, weapons, armor, accessories, and newly acquired movement or traversal abilities. The compilation also provides access to both separate adventures from its game-selection screen.

Map the castle methodically and revisit rooms after gaining new abilities; important paths, items, and optional areas are often inaccessible on the first visit.

Upgrade equipment regularly, test new magic or relic combinations, and save before bosses. In Circle of the Moon, experiment with DSS pairings, while in Harmony of Dissonance, compare equipment effects instead of judging items only by attack power.