Usually in fantasy games with dungeon quests, you are the good guy and must progress through the dungeon, killing baddies in order to progress until you reach the object of your quest. From time to time, you are the bad guy and must set up your dungeon lair in order to kill as many invading heroes as possible. In a twist on the usual formulae, however, in Dungeon Maker you are the good guy, digging a dungeon with your magic shovel in order to attract all kinds of monsters and dispatch them so that they can't terrorise your town.
You'll have to be clever to lay out your dungeon, and furnish it to attract larger and larger monsters. Killing them will enable to you collect items they drop and sell them to equip yourself and gain magical attacks. You can also collect their bodies and make meals from them when you have the appropriate recipes. Eating these meals will enable you to enhance your statistics.
You'll be joined on your quest by your friend Kate and a Mimic Slime called Gloop. Both of these characters will assist you in defeating the monsters. You'll also be able to swap your dungeons with other players using the DS's wireless communication capabilities by visiting the ruins just outside of town.