Dig Dug is a 1-2 player arcade game where you have to use your shovel to dig through the earth. Two monsters, Pooka and Fygar, will chase you around, trying to stop you. Your only weapon is an air pump, which can be used to inflate the monsters until they explode. You can also use rocks to squash certain obstacles. If the monsters don't find you for a few seconds, they'll turn into ghosts that can walk through the earth. They're invincible and can't be killed. Occasionally, vegetables will appear in the center of the screen, giving you points.
The gameplay involves using your shovel to dig through the earth, avoiding the monsters and collecting rocks and vegetables along the way. You'll need to inflate the monsters with your air pump when they're close, and use rocks to clear any obstacles that get in your way. The goal is to make it as far as you can without getting caught by the ghosts or running out of health.