DIG DUG

I still cant get this achievement its a tough one
Video link
http://au.youtube.com/watch?v=iZarxOZxTAM

Ok, there are 2 things to know about this achievement

1) You do not have to beat the level to get the achievement (I actually unlocked it after i dug everything and one of those stupid things I was keeping alive killed me)

2) You *MUST* Re-dig up the initial vertical tunnel you came down. This is what I had forgot to do the 6+ times I cleared the screen before I unlocked this. The problem is the dirt is invisible (go figure).

So to make sure I did step 2, I start by digging down, go to the dragon tunnel, kill that, wrap around and free the bottom rock. Cross over to the red thingy on the right side. pop him then drop the rock next to him. Then I start sweeping the bottom. Once I clear the bottom to where the initial vertical tunnel drops you, I just went straight up that tunnel to get it out of the way. then just continue to clear out the screen. As I stated, you actually don't have to kill all the enemies or let 1 escape to get the achievement, chances are if it is not unlocking for you, its because you did not re-dig the initial tunnel vertically you came in on and one of the pieces of invisibile dirt are still there.

After 20 attempts and 5 complete screen clears, I knew this achievement was tricky. This is how I finally unlocked it on Level 1:

1. Kill the Fryga (the green dragon).
2. Kill one Pooka (orange, round thing). Leave two Pooka's alive.
3. Set off the rocks to fall to get rid of them. That way they break, freeing up space for you to clear later. Again, free the rocks so that they are wasted and break and won't kill anything. Do NOT crush monsters with them.

4. As you dig dirt, if the two remaining Pookas are closing in on you, pump them up a little bit to slow them down. Three pumps is the max. No more than three or they will explode. If you kill all but one monster, it will run away and the level will end, resetting all the dirt you worked so hard to dig. Keeping two Pookas alive will ensure that the level lasts long enough for you to dig completely.

5. Retrace the entrance shaft.
6. Retrace Dig Dug's starting point.
7. Walk the surface.
8. Retrace the monster rooms.
9. Clear the dirt.
10. Kill the two remaining monsters.

11. Finish and move on to Level 2. This is VERY important. If you clear the dirt in Level 1 and commit suicide before reaching Level 2, you can kiss that achievement goodbye.

12. At Level 2, feel free to commit suicide. When you get the "Game Over" message and go to the achievements screen, the achievement will pop.

When doing this achievement, keep in mind that you must walk through every inch of the level, inlcuding the tunnel created when you start, the top of the level and the tunnels that the monsters walk around in.
Also, keep two enemies alive, as killing one of the last two will cause the last one to exit the level and end it.
Most importantly, after walking through every inch of the level, it is an excellent idea to walk around the entire edge of the map clockwise and then counterclockwise.
Unlike some have posted, finishing the level is not necessary. After I did as described above, I let the last 2 enemies kill me. The achievement popped when my lives ran out.
As other have posted, it is best to do this on the first level and to kill the dragon as well as one other enemy.
One final tip: enemies are easiest to deal with if you walk in long straight lines. After a few seconds they tend to walk on directly behind you, making it easy to turn around and pump them. But remember, if you only have 2 enemies left, only pump them a maximum of 3 times.

Start on level 1.
Immediately dig down and inflate & kill the lower two enemies. Then, sweep the level horizontally or vertically without digging into the two 'starting areas' for the upper enemies. You want to leave those start areas intact as long as you can, since if you die, the enemies will respawn there and you'll get a few more minutes of clearing time until they get out to go after you.

Be careful to trigger the rocks to fall as soon as you can in such a way that they WON'T hit the two remaining enemies - if one dies, then the other will get away and you'll progress to the next level. If an enemy gets close, inflate it three times, then take off in an "L" movement - move vertically a ways then horizontally - this will get you away and buy you some time when they recover. If both get close, you should have time to inflate them each at least once (hopefully twice), and then escape in the same manner.

When you're down to sweeping the smaller bits, you may find clearing out quadrants (lower left, upper right, etc) works best. Clear as much as you can while the enemies work their way down to you, then boot it for another section and start sweeping there.

When you've swept it all, you should only have the short 1/2 height vertical spots along the top (undiggable), and dug space all along the outside edges of the playing field. Inflate one or both of the remaining enemies and progress to the level 2. Continue playing normally or get yourself killed - either way, the achievement will unlock when your game is complete.

Edit: What's with the negative votes - any voters want to explain what was bad about this solution? I know it's the oldest one posted, but c'mon.

This achievement is quite the tough one I recently got it, but it took me many tries here's some pointers since videos don't really help you here.
- Kill the dragon first his sporadic firing is to risky to keep him alive and you can kill one ghost as well to make life easier
-Next go around and make all the rocks fall, for this will help you later in the game when you risk dropping a rock on one of the last two ghosts.
-Whenever the last two ghosts get to close, you can put two blows of air without making them explode
- I always try to eliminate the top section since its the most difficult section
-I go vertically across the map first since its easier and makes it more simple when you have to go horizontally.
It will take many, many tries but with the right amount of skill and some luck it is possible to get.

I just achieved this and none of the solutions I read really helped much, so I came up with my own strategy, and it worked after a few tries.
1> Kill off the leftmost two enemies right away (pygar then pooka), and move towards the left side of the screen ASAP with as little digging as you can. Use their caves as your path to the left side, using the upper left pooka cave on your way to the top.
2> Here's the idea... you want to start doing vertical passes with the least amount of horizontal passes until you're done with the verticals. So once you get to the top (the blue area) go left and then all the way down. Do a U turn and go most of the way back up until you get to the area you started going vertical first after killing the pygar.
3> Around now you'll have to start worrying about the other two pookas as they'll have escaped their caves and headed your way. Remember that you can pump them up TWICE without them exploding and use this to slow them down. It's tedious but you need to preserve your lives until the very end. Obviously, if you kill one of the remaining pookas, the level will end because the other will hightail it for the hills.
4> Here's where my strategy comes in. So you've got two vertical passes done. Go to the right and start another, then do them uniformly one after the other, keeping the pookas at bay until you reach the right side. I like to do them without breaking the walls at the bottom, because when the pookas are chasing you, it gives them less direct routes to get in your way. This is really the whole point of doing the systematic vertical THEN horizontal approach. You need them to work hard to get at you so you have more time to dig.
5> Eventually the "hurry up" music will start and they'll chase after you even faster. It gets pretty hairy after a while. Try not to lose a life until you're done with all the vertical passes. On your last vertical pass, on the far right side, from the top upper right corner,make sure you make one big horizontal pass along the blue area to the left side, as it seems to be required.
6> Now we start the horizontal passes. I like to start at the bottom and work my way up. I don't think it matters much though. The key is to NOT cut holes sideways closely for them to get at you through. So I run one across the bottom, then skip the next horizontal up, and run one back a level above the next, so when they're chasing me they don't have easy access. You want them to have to travel a long ways vertically- they never turn around or double back, so once they're going vertical you don't have to worry about them until they can come around a corner and back.
7> As you finish horizontals one by one, alternating rows, you'll start running out of ways to dodge them, so be super careful to keep inflating them every few seconds. Hopefully you saved your lives for the end, because when you get down to four rows it gets almost impossible to dodge them.
8> When done, inflate the remaining ones and go to the next level. I saw other people say you don't need to, but really, what's the harm? I didn't once, and the achievement didn't pop for me even though I cleared the whole level. I'm pretty sure you need to finish the level.

To summarize, the real strategy here is to keep the horizontal walls around as long as possible so the pookas have to work a lot harder to get at you, and once they start going down the wrong path you have some breathing room. It gets harder and harder as you near finishing, but doing every ALTERNATE horizontal row makes it a little less frustrating.

Good luck, and don't feel frustrated- this is a very hard and annoying achievement, for sure. Take a break after a while.