In a world overrun by vampires, a group of nuns with their own stories have arrived at the Hunters' Guild. They are ready to wield any power—even that of demons—to defeat their enemies. What fate awaits them on this perilous journey?

The developer describes the content as follows:
When characters level up or interact with NPCs, illustrations featuring revealing clothing are displayed.
In the ending scenes, illustrations show each character wearing revealing outfits and posing seductively.

Nunholy is an action-packed roguelike game where you explore dungeons and hunt down vampires as battle-hardened nuns.

Each time you slay a vampire, you can absorb their power to grow stronger or sell it to upgrade your gear. Will you embrace the vampires’ dark power, or rely solely on human strength? The choice is yours.

Vampires come in many forms and ranks—Knights, Barons, Counts, and Dukes—each stronger than the last. Hunt down the most powerful of them all and prove yourself as an S-rank hunter.

Within the dungeons, you'll encounter merchants, witches, prisoners, and undertakers—people who care little about who you are, as long as you can pay. Meet them, trade with them, and prepare for the hunt.