Inspired by Bullfrog's Dungeon Keeper, Kalypso's Dungeons has you playing as an evil dungeon master who must build an underground lair designed to lure treasure-seeking heroes. Why entice heroes to come to your lair, you ask? So you can harvest their energy and become more powerful.
The story involves trying to reclaim your rightful place at the top of the underworld hierarchy after being framed by your ex-girlfriend Calypso. Your new "bosses" include the Zombie King and a warmongering creature named Minos, who along with Calypso, must be eliminated to restore order. The campaign has you trying to defeat all three dungeon lords over the course of 17 missions.
To succeed, you'll first need to expand your influence by ordering goblin workers to dig out tunnels and rooms. You can then place various objects to impede each hero type's progress. Since your dungeon is vulnerable, you need to carefully build traps and monster-spawning rooms to protect the dungeon's beating heart. After you've conquered the campaign, you'll be able to continue building dungeons from within the game's sandbox mode.