Joystick: Use the 4-way joystick, to direct your Dig Dug (white for 1P, yellow for 2P) around each of the game's rounds; they can't dig through metal.
Button: Use the button to make your Dig Dug pump up the enemies until they explode; if caught on the pump of a Black Dig Dug, press it repeatedly to shake him off (you also have to do this if he, or the other Dig Dug in a two-player game, starts pumping you up to prevent yourself from exploding)
1 or 2 Player Buttons: Push these buttons to begin the game as player 1 or player 2; in a two-player game, both players' scores shall be combined.
Dig Dug (Taizo Hori) is the protagonist of this game, but this time, there's two of him; Player 1 controls the original white-suited version of him on the left while Player 2 controls the new yellow-suited version of him on the right. A two-player game is semi-cooperative (like in the original Mario Bros.) - for both players will have to work together to kill all the enemies (of which there are seven new types), but one player may either pump the other one up to kill him for 10000 points, or drop a rock on him to crush him (in the case of the latter, the text of "Betrayer!" will appear on the screen). At the end of a round in a two-player game, the text "RESULT" will appear on the screen, with the number of enemies both players killed by pumping, rock-dropping, and Cosmo Ball-dropping (however, on many rounds, there are no Cosmo Balls, so for those rounds it will always be 0 for both players) below it; the amount of points that both players scored on the round will also be displayed below them, and the text "1P/2P Win!" will then appear at the bottom of the screen (depending on which player had got the higher score). Both Dig Dugs also get an extra life when their separate scores reach 50000 points.
As in the original Dig Dug, if either player digs away the earth underneath a rock, it shall fall to the bottom of the shaft it was at the top of, crushing any enemies in its path on the way down (and either Dig Dug, if you or the other player could not get out of its way in time!); however, there are now also Big Rocks (which shall fall straight to the bottom of the screen, when loosened), Cosmo Balls (from Cosmo Gang: The Puzzle, which will roll in the direction the arrows on them are facing when loosened) and Containers (from both Cosmo Gang games, which will take the place of the Rocks from Round 31, the first on the Moon, onwards). Refer to the charts below to find out the amount points you will receive for the number of enemies you crush:
Boots: These appear every time either Dig Dug walks 320 pixels and when it is collected for 100 points his speed will be increased until the next time he loses a life (unless he collects the Lock); the appearances of the special bonus items are not random but are determined by specific actions.
Red Pump: This appears every time either Dig Dug launches his pump 32 times, and when it is collected for 200 points, it will increase its range.
Blue Pump: This appears every time either Dig Dug kills sixteen enemies and when it's collected for 200 points it will increase his pump's speed.
Green Pump: This appears every time either Dig Dug goes up to the surface 96 times, and when it is collected, for 200 points, it will increase his pump's inflation speed; because the Dig Dugs do not have to go up onto the surface all that often you might not actually see this special bonus item.
Yellow Pump: This appears if either Dig Dug is killed more than four times in a two-player game and when it's collected for 400 points it will give him the effects of the other three pumps; if you and your friend can finish it, without dying four times, you may not see this special bonus item either.
Lock: This appears every time either Dig Dug walks 256 (16 x 16) pixels, and when it is collected for 1000 points the effects of any other special bonus items will not be lost the next time he loses a life, except that of the Green Balance which causes regular bonus items to appear immediately.
Green Hourglass: This appears every time three enemies escape off the top-left side of the screen, and when it is collected for 1000 points, the playfield will turn brown as all remaining enemies are immediately almost fully inflated; however, it only lasts ten seconds, so you'll have to be quick.
Yellow Hourglass: This appears every time the Ghosts (which aren't the same as those ones from Namco's own Pac-Man series!) appear twice for taking too long over a round, but when it is collected for 5000 points the text "Hurry Up!" will immediately appear on the screen as a result of this.
Yellow Rod: This appears every time either Dig Dug drops six Rocks (or Containers, from Round 31 onwards), and when it is collected for 1000 points, it will cause a shower of meteorites to fall down from the top of the screen that will crush all enemies beneath them as they go to the bottom.
Blue Rod: This appears every time either Dig Dug loosens six Cosmo Balls, and when it is collected (for 1000 points), it shall cause a shower of bullets to fall down from the top of the screen that will chip away at the earth (unless it has already been dug away) and kill off any enemies they hit.
Ray Gun: This appears every time either Dig Dug collects six pairs of Boots or Pumps, and when it is collected for 2000 points, it will replace his pump for eight shots; they also appear on Rounds 24, 40 and 50, as they must be used to defeat the bosses there, and have unlimited ammunition.
Barrier: This appears every time either Dig Dug loosens sixteen Cosmo Balls, and when it is collected, for 1000 points, it'll generate a force field around him which renders him invulnerable for a while; it will flicker when it is about to wear off so you should be sure not to be on top of an enemy.
Rally-X Special Flag: This appears every time either Dig Dug dies then goes ten rounds without it happening again, and when it is collected for 100 points, it will give him an extra life; they also appear in every regular round of Rally-X Arrangement including in the form of the new Item Flags.
Yellow Balance: This appears every time either Dig Dug goes six rounds without dying, and when it is collected for 1000 points it will cause the enemies to leave 500-point rings (if exploded) and 2000-point necklaces (if crushed) behind when killed; however, they will disappear after a while.
Green Balance: This appears every time either Dig Dug eats four, eight, sixteen or twenty-four regular bonus items, and when it is collected for 1000 points, it will cause the regular bonus items to appear immediately at the start of a round, as opposed to once two Rocks have been dropped.
Tea Gourd: This appears every time both Dig Dugs start a round (having not collected any other special bonus items), and it is worth 10 points.
Green Gourd: There is also a 1-in-32 chance of this appearing, when both Dig Dugs start a round having not collected any other special bonus items, and when it is collected it shall cause one of seven random things to happen: 1: A random bonus of 10-5000 points, 2: A top will appear and move in the manner of a Cosmo Ball, 3: Ten rings and necklaces will be randomly scattered over the maze, 4: The text "Hurry Up" will immediately appear, 5: All Rocks (or Containers) and Cosmo Balls shall be shattered, 6: All remaining earth will immediately disappear and cause all remaining Rocks (or Containers) and Cosmo Balls to fall down to the bottom of it, 7: Explosions will occur all over the maze, killing all the remaining enemies.