9 Kings is an early access game where players defend their kingdom using cards to strategically place units and buildings against aggressive monarchs. Upgrading units and buildings is done by overlaying cards, and spells can provide new abilities. Players can acquire cards from various themes during battles, allowing for diverse builds.
The King is Watching features grid-based gameplay and kingdom defense but lacks the fluidity of 9 Kings, requiring significant time investment for resource grinding. It introduces a mechanic where players must keep their gaze on buildings for them to function, adding tension and strategy.
Drop Duchy reimagines Tetris as a kingdom-building roguelike deckbuilder, where players use tetrominos generated from cards to construct their kingdoms. Building prerequisites depend on surrounding tetrominos, and completing lines rewards players with resource bonuses.
These three games showcase diversity within the deckbuilding genre, each offering a unique experience while sharing foundational elements.