Level 6 walkthrough:
From the entrance, go east twice, kill the enemies, and push a block to reveal a passage.
You arrive in a room with a Like Like. Go east once, collect the key, and then go east again (if desired, the prize there is the compass).
Backtrack west 2 rooms. Bomb the south wall and proceed.
Kill the enemies, collect the 5 rupees, then open the door to the east. You should now have no keys (unless you have extra from previous levels, which I do not rely on).
A room full of Red Darknuts and the boss door to the east. Kill them if you need bombs. If you don't, you can just bomb the south wall and proceed.
Aha, a new enemy! Kill these guys, and push the block to open a passage. Note the southern door that you have no key to open.
A room with 3 Dodongo Babies, and 2 Keese. Should be simple by now. You can go west or north, but let's go west first as that is optimal.
Ah, a new tricky room. Looks like the key you need is held on the other side of those blocks. Kill what you can, then use your whistle (you did purchase the hint from an info-seller in the OW, right?) Walk to the other side of the room and finish up, collecting the key, then backtrack east.
Go north this time.
Optionally, kill these Zols and stand in the sand when you blow the whistle. That gets you the map. If going for speed, just continue west.
Simple room, kill the Keese, or not, up to you. There is a hidden path here, but you don't know that yet. Continue west.
Go north, it's all you can do.
Go west again. Kill the enemies if you like, it can make it easier the next time you pass this way.
Ugh, a push-the-block-room. You can't go backwards, but you can go north (with your key) or south, if you missed it.
Either way you go, you're going to come right back into this room. If you had the ladder already, and went south, then you could take a shortcut back to the entrance, but you don't have the ladder yet.
Back in the block room, push it again, going the only way you can, which west.
Kill the Ropes in this room. I suggest bombing the north wall for a hint that will be useful very soon, if it weren't so cryptic. Damn you, Imzogelmo!
In the Rope room, go west. Lots of going west in this dungeon.
Since you were good and took the hint, you know what to do here. Kill the Keese if they get in your way as you maneuver the invisible maze and go south.
A room full of Red Bubbles. Tread carefully, and go south. The odd lava tiles are a hint, not a bug.
Kill some of the Gibdos if you need bombs. Now you have a choice, east or west. Optimally, go east
Kill the Dodongos. Or don't. You don't win anything here. Bomb the east wall, and go in, grabbing a key.
Back into the Dodongo room, you can go south or west. Optimally, go back west.
Go wet again. A money or life room, oh no! Pay up, and go north.
Kill the Patra, or if you are weak, just run. Use the key you have and go north.
Using the blocks as cover, kill the zillion Darknuts, which should be a hint that this is an important room. Push a block, and collect the ladder (finally!).
Go back south, south, east, east, to the old Dodongo room, only this time, go south.
Kill the enemies here, for a key. Then bomb the west wall and proceed.
Go west again, using that last key.
Kill all the surprisingly easy enemies, but do it blindly, as the floor is invisible. Collect the boss key.
Now to backtrack. East, east, north, west, nroth, north, east, east..push the block...north, north. Cross the lava this time, and open the boss door.
Not that hard of a boss, considering the level. I killed it in one hit, but that was probably luck. Go south, to the Triforce room.
If you want the sword swipe, ignore the Triforce and bomb the south wall.
Go east, talk to the old man for a clue about an upcoming enemy. Go east again.
Kill the Gleeok, find the passage.
Kill the Gibdos. If you leave the room, it takes you eventually out of the dungeon, collecting an extra key on the way. This is fine, but not what I suggest. Find the passage in here, and take it....
A room with Baby Dodongos? Yep. Run away, nothing to see here. You have to go west from here.
Collect the sword slash technique, then go west to walk out, or go east and take the passage back to the room with the Gleeok. I suggest the latter.
Backtrack west twice, then north, collect the Triforce. You're done!