Cuthbert, Microdeal's mascot, is trapped inside a mine, filled with crawly creeps. He must climb the ladders out of the mine and reach the surface before the oxygen level reaches zero.
Each floor in the mine is filled with creeps, and Cuthbert's only weapon is his mining pick-axe. Using the axe, he can pick holes in the floor that the creeps fall into. Trapped in the holes, they are defenceless against Cuthbert's axe. Once Cuthbert has reached the surface, he goes on to the next level.
As you may have figured out, Cuthbert Goes Digging is essentially based upon Space Panic.