Dig Dug (1982)

Each level is a cross-section of dirt with tunnels dug in real time as the player moves.

The two types of enemies encountered are Pookas, round red creatures wearing goggles, and Fygars, green fire-breathing dragons.

Both pursue the player through tunnels, and after a few seconds of losing sight of the player, they can transform into ghostly forms to move through solid earth until they reach another tunnel.

To defeat enemies, the player carries an air pump that can be attached by pressing the action button.

Pumping inflates the monster until it bursts, awarding points.

Pumping can be interrupted, but partially inflated enemies will revert to normal and continue attacking.

An alternative method of attack is luring enemies under large rocks scattered throughout each stage.

Digging beneath these rocks can cause them to fall, crushing anything below, including the player.

Rocks falling also open tunnels, and dropping multiple rocks in a stage grants bonus points.

Scoring incentives are built into the system.

Vegetables occasionally appear in the middle of the screen once two rocks have been dropped in a round.

Collecting these vegetables grants bonus points, and the type and value of the vegetable increase in later rounds.

Bonus points are also awarded for consecutive ghost kills or for crushing multiple enemies with a single rock.

Each round ends when all enemies have been eliminated.

Enemies increase in speed as stages progress, and Fygars add the additional threat of breathing fire horizontally across tunnels, which can instantly defeat the player.

Later versions and home releases varied in presentation and features.

The arcade original allowed two players to take turns, while console and computer ports often adjusted graphics and sound to suit hardware limitations.

Some versions altered maze size, e